SCOPTSCOPT Inc.
Simulation software

HHCT — HAPS-to-HAPS Communication Simulator

The HAPS to HAPS Communication Tool (HHCT) is a standalone Windows application for simulating optical (FSO) or radio-frequency (RF) communication links between two High-Altitude Pl

Overview

The HAPS to HAPS Communication Tool (HHCT) is a standalone Windows application for simulating optical (FSO) or radio-frequency (RF) communication links between two High-Altitude Platform Stations (HAPS) in the stratosphere (endpoint altitudes 15-40 km, typically 18-22 km). Operating above weather, cloud, and rain, HAPS-to-HAPS links offer low-latency, high-throughput connectivity for aerial backbone and inter-platform networks - yet remain sensitive to pointing error, beam divergence, platform drift, residual turbulence, and (for RF) gaseous absorption. HHCT provides rigorous, Monte-Carlo-based performance analysis for communication engineers, aerospace planners, and researchers.

Note: Delivered as a self-contained compiled Windows executable - no MATLAB, no Python, no external runtime required.

Key features

  • Two link types (chosen on the home screen): FSO Optical (default 1550 nm) and RF (default Ka-band 30 GHz).
  • Full HAPS-to-HAPS geometry: Uplink / Downlink / Horizontal, adjustable altitudes (15–40 km), elevation, and distance, with live slant-path readout.
  • FSO modeling: six turbulence models (Gamma-Gamma, F, Lognormal, M laga, Weibull, Exp-Weibull) via HV 5/7 + Rytov; layered Beer–Lambert attenuation (Kim clear-air + optional Cloud, Fog, Volcanic); pointing error (Rayleigh/Hoyt/Beckmann); AoA with FoV mask; Gaussian/plane/spherical beams.
  • RF modeling (ITU-R): Rician / Nakagami-m / Shadowed-Rician fading; P.676 gaseous absorption; P.525 FSPL; direction-dependent antenna noise (P.372/P.618). Rain/cloud/tropo-scintillation excluded by design (path 15 km).
  • Detection & modulation: IM/DD (OOK), Heterodyne (BPSK, M-PSK, M-QAM).
  • Metrics (4 tabs): Average BER, Ergodic Capacity, Outage Probability, Link Budget (power/loss/margin; C/N for RF).
  • Monte-Carlo engine with parametric batch sweeps over any axis; multi-curve overlay.
  • Independently validated (report ships with the tool).

Use cases

  • Aerial Network Designers: Feasibility and link-margin studies for long-range, point-to-point HAPS-to-HAPS backbone links.
  • Telecommunication Operators: Backhaul performance evaluation for rural or emergency coverage.
  • Aerospace Engineers: System-tolerance analysis for optical and RF payloads under platform drift, pointing jitter, and residual turbulence.
  • Research & Education: Teaching and studying the physics and performance limits of near-space (stratospheric) communication systems.

System requirements

  • Operating System: Windows 10 / 11 (64-bit)
  • Software Dependencies: None - no MATLAB, no MATLAB Runtime (MCR), and no Python required. The tool is a fully self-contained compiled executable; everything it needs is bundled in the installer.
  • Memory: 4 GB RAM minimum (8 GB recommended for large Monte-Carlo runs)
  • Disk Space: ~250 MB
  • Connectivity: None required - runs entirely offline