European Space Agency

3GNet Sim - Network Simulator for Third Generation Mobile Satellite Systems


The objectives of this activity are threefold:

  1. To design, develop, and validate a modular and efficient radio access network simulator for third generation mobile satellite systems;

  2. To carry out simulation runs with a view to optimise the simulated system; and

  3. Based on a thorough analysis of the simulation results, to contribute to the standardisation of the higher layer protocols involved.


The 3G satellite network simulator covers in particular these two core capabilities:

  • The capability to perform a thorough analysis of satellite UMTS radio access networks; and

  • The capability to study the interworking of the satellite UMTS radio access networks with the terrestrial UMTS IP core networks.


The main benefits expected from this activity are:

  • To demonstrate the technical feasibility of satellite UMTS radio access networks and their compatibility with terrestrial UMTS core networks;

  • To develop, validate and optimise key concepts and procedures of satellite UMTS radio access networks using simulation; and

  • To contribute to the S-UMTS standardisation process.


The following figure provides a high-level sketch of the simulator architecture.

click for larger image
     As indicated in the figure, the overall simulator is composed of two components, the Protocol Simulator and the Network Performance Simulator. Both simulator components are based on the commercial tool OPNET Modeler, whereby the Protocol Simulator employs specialized OPNET models, in particular the UMTS Model, which provides UMTS-specific functionality.

The Protocol Simulator models the protocols and procedures of the Uu and Iu interfaces in a detailed and comprehensive way. The Network Performance Simulator models aspects such as traffic generation, application characteristics, user mobility, network resources, and signalling and traffic load at a high level of abstraction.

The input and output data, as well as the interdependency of the two simulator components are also indicated in the figure.


The study was initiated in early 2003 with the final delivery scheduled for October/November 2004. The activities are organised into several steps as sketched in the following diagram:

click for larger image

Current status

The simulation and optimisation runs were completed and the draft final delivery package was submitted in October 2004. The Final Presentation is foreseen for 28 January 2005.

Status date

Thursday, March 20, 2008 - 09:11