SCNE Simulator Description

The SCNE (Satellite Constellation Network Emulator) is a simulator for Non-Geostationary Satellite Orbit (NGSO) satellite mega-constellation network higher protocol layer performance analysis. The main adopted design assumptions for the SCNE can be listed as:

  • De-coupled orbital and network simulator architecture – providing the benefits of two different tools for orbital and network simulation. Capability of run the orbital and network simulators separately.

  • Capability of designing satellite constellations with no restrictions.

  • Non-Real Time (NRT) simulator – Network simulation is a complex time demanding function which depends hugely on the complexity of the models and size of the simulation scenario.

  • Per-packet level operation – The target is to evaluate the higher layer communication protocols operating on a packet resolution.

  • Open-source network simulator – allowing the users to build their protocols, features and algorithms of interest.

The SCNE is composed of three main components: the orbital simulator (STK), the network simulator (ns-3) and the SCNE orchestrator.

AGI's STK tool is commercial software. There is a free version of STK, but the SCNE requires a full STK license with additional Professional and Com module licenses. In SCNE, the STK is used as an orbital simulator

  • to model the SCNE physical and communication objects, i.e., UT, GW and satellite nodes and their transmitters and receivers

  • to create the link characteristics to be used as the network simulator input

Network Simulator 3 (ns-3) is a discrete-event network simulator, targeted primarily for research and educational use. Ns-3 is free software, licensed under the GNU GPLv2 license, and is publicly available for research, development, and commercial use. In SCNE, the ns-3 simulator is used as a network simulator:

  • to model the lower layer packet operations, such as packet transmissions over the channels, by utilizing the link characteristics provided by the STK

  • to model the higher layer packet operations, such as routing, by implementing various higher layer protocols

  • to model the traffic by implementing various applications (traffic generators)

The SCNE orchestrator is an SCNE plugin, which is used:

  • to create the required configuration data based on the STK scenario for ns-3

  • to configure and command the STK to form the required link characteristics and other input data for ns-3

The SCNE ns-3 simulator has been integrated to Magister SimLab. The default STK satellite scenario is 24 hours long and consists of 288 satellites within circular quasi-polar LEO orbits, 10 gateways (GW), and 50 user terminals (UT). Each LEO satellite is configured with 4 ISL links. If one wants to modify the satellite constellation specifications or create a new constellation, it needs to be done using the STK tool.

SCNE use cases are e.g.

  • Adaptive algorithms for ISL routing in space

  • Transport layer performance

  • End-to-end application performance