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Modules

ns3-ntn-toolkit ships 13 integrated ns-3 contrib modules that together simulate a complete 5G/6G non-terrestrial network - orbit to application layer. Every module is independently testable, ships its own examples, and builds from a single ./ns3 build. Pick the layer you research; the rest compose around it.

How to read this page. The modules are grouped by the part of the non-terrestrial stack they model. Each links to a deep-dive page with what it simulates, the 3GPP / ITU-R / O-RAN standards it aligns to, concrete use cases, and a runnable example.

Orbital & mobility plane

Module What it simulates
ntn-constellation SGP4/SDP4 LEO/MEO/GEO orbit propagation from real Starlink / OneWeb / Kuiper / Iridium TLEs; Walker-Delta / Walker-Star mega-constellation generators; contact-graph routing.
ntn-sagin Space-air-ground integrated networks: HAPS station-keeping, UAV/drone patterns, aviation (ADS-B) and maritime (AIS) UE mobility, high-speed train channels.
ntn-v2x Vehicle-to-everything over LEO: vehicular UEs (SUMO traces), direct-vs-relay selection on measured SINR, V2X-NTN connectivity for rural and highway coverage.

Protocol stack (L1–L3)

Module What it simulates
ntn-rrc 3GPP Rel-17/18 NR-NTN control plane: SIB19 ephemeris, common + UE-specific Timing Advance pre-compensation, GNSS UE location reporting, NTN-extended DRX.
ntn-cho Rel-17/18 conditional handover for LEO with the full NTN trigger set (A3, location condEventD1, time condEventT1, timing-advance, elevation, Rel-18 condEventD2) and a TTE-aware algorithm.
ntn-slice 5G network slicing over NTN: eMBB / URLLC / mMTC slices sharing a real NR cell with per-slice measured SINR and SLA-breach detection over the LEO slant.

Physical layer & channels

Module What it simulates
thz-ntn 100 GHz – 1 THz physics for NTN: HITRAN molecular absorption, ITU-R P.676/P.618/P.838 cascade, UM-MIMO, RIS, ISAC, EKF beam tracking.
ntn-sionna NVIDIA Sionna RT ray-traced channels bridged into ns-3: multi-tap CIR, Doppler synthesis, ITU-R atmospheric cascade, MIMO.
satellite (SNS3) The vendored CNES/Magister SNS3 base: SatSGP4 mobility, SatChannel, DVB-S2/S2X/RCS2 link results, inter-satellite links.

Control, intelligence & operations

Module What it simulates
oran-ntn + FlexRIC O-RAN Near-RT RIC + on-board Space RIC with xApps, real E2AP/E2SM ASN.1-PER over SCTP, FlexRIC bridge, measured TS 28.552 KPM.
ns3-ai-ntn AI/ML for satellite RANs: ns3-ai shared-memory bridge, Gymnasium environments, reinforcement-learning control loops.
ntn-observability Measured-KPI observability: InfluxDB + Grafana sinks, NetSimulyzer 3D export, Cesium globe, reproducibility manifests.
ntn-digital-twin Live constellation digital twin: real-time TLE propagation, FastAPI prediction service, closed-loop event driver.

Each module page is a standalone deep dive. Start with the getting-started guide to build the whole toolkit, then jump to the layer you research.