The idea
Spectrum compliance modelling has traditionally lived in desktop tools on a single engineer's machine. SpecSim moves it to the cloud: upload a CSV of radio sites, run the propagation simulations on a server, and see the resulting device boundaries drawn on a map in the browser — shareable, repeatable, and not tied to one laptop.
How it works
Each site in the upload is routed to a band-specific simulation engine — Modified Hata at 2.1 GHz, ITU-R P.452 and P.526 at 2.3 GHz, and ITU-R methods across 3.4–3.7 GHz. The models run over real inputs: DEM-3S elevation data and a library of around two thousand antenna patterns. Jobs are queued to async workers, results are stored in Postgres, and device boundaries are rendered as polygons on a Leaflet map.
Architecture
A FastAPI backend with Celery and Redis for the job queue, a Next.js and React-Leaflet frontend, PostgreSQL for results, and rasterio for elevation I/O — the whole stack runs as a set of containers under Docker Compose. The physics, API, and worker layers are covered by 76 automated tests, so the engine can be changed with confidence.
Status
A prototype with Phase 1 complete: the simulation engine is stable and the web UI works locally. Cloud deployment and multi-tenant access are the next steps.