Satellite Network Simulator 3 (SNS-3) is a satellite network extension to Network Simulator 3 (ns-3) platform. SNS-3 was initially developed by Magister Solutions under ESA contact.

SNS-3 is distributed under the GPLv3 license.

Some external modules have been partially or totally integrated to SNS-3:

• lorawan, with license GPLv2
• SGP4 satellite movement, with license GPLv2
• ISL routing, with license GPLv2

SNS-3 is built as an extension module to the NS-3 network simulator; so their installation instructions apply, particularly concerning the dependencies. They are repeated here for convenience and proper integration of SNS-3.

This revision of SNS-3 is compatible with NS-3.37.

There are 2 methods to download and build (S)NS-3:

• the automated one using bake;
• the manual one using CMake.

Bake is a tool developed to simplify the download and install process of NS-3. It can be extended to make it aware of external modules to NS-3 such as SNS-3. You will first need to get bake.

First you need to download Bake using Git, go to where you want Bake to be installed and call

$ git clone https://gitlab.com/nsnam/bake

It is advisable to add bake to your path

$ export BAKE_HOME=`pwd`/bake
$ export PATH=$PATH:$BAKE_HOME
$ export PYTHONPATH=$PYTHONPATH:$BAKE_HOME

Before installing NS-3, you will need to tell Bake how to find and download the SNS-3 extension module. To do so, you will have to create a contrib folder inside the newly acquired bake folder:

$ cd bake
$ mkdir contrib
$ ls
bake  bakeconf.xml  bake.py  contrib  doc  examples  generate-binary.py  test  TODO

and drop the following file sns3.xml in this contrib folder:

<configuration>
  <modules>
    <module name="sns3-satellite" type="ns-contrib" min_version="ns-3.37">
      <source type="git">
        <attribute name="url" value="https://github.com/sns3/sns3-satellite.git"/>
        <attribute name="module_directory" value="satellite"/>
      </source>
      <build type="none">
      </build>
    </module>
    <module name="sns3-stats" type="ns-contrib" min_version="ns-3.37">
      <source type="git">
        <attribute name="url" value="https://github.com/sns3/stats.git"/>
        <attribute name="module_directory" value="magister-stats"/>
      </source>
      <build type="none">
      </build>
    </module>
    <module name="sns3-traffic" type="ns-contrib" min_version="ns-3.37">
      <source type="git">
        <attribute name="url" value="https://github.com/sns3/traffic.git" />
        <attribute name="module_directory" value="traffic"/>
      </source>
      <build type="none">
      </build>
    </module>
  </modules>
</configuration>

This configuration file is used to get all the NS-3 modules needed to compile SNS-3. By default, for each module, bake takes the most recent commit on master. If you want a specific commit for a module, add the following line (with the wanted revision in value) between the flags <attribute name="url" ...> and <attribute name="module_directory" ...>:

<attribute name="revision" value="72aa513f43b7687336cf6251d50e81420c41691f"/>

It might be necessary to remove the default bake configuration one in order to install SNS-3:

$ rm bakefile.xml

Now you’re ready to use bake.

Now that everything is in place, you can tell bake that you want to install SNS-3 (i.e.: ns-3 plus the sns3-satellite module):

$ ./bake.py configure -e ns-3.37 -e sns3-satellite -e sns3-stats -e sns3-traffic
$ ./bake.py deploy

This will download the needed dependencies into a source folder and call the various build tools on each target. If bake finds that tools are missing on your system to download or build the various dependencies it will warn you and abort the build process if the dependency wasn't optional. You can ask bake for a summary of the required tools before deploying:

$ ./bake.py check

If you wish to have finer control over what is being compiled, you can handle the download process of the dependencies yourself and use CMake directly to build NS-3.

You will need to:

• get NS-3 (either by downloading it or cloning it using git);

$ git clone https://gitlab.com/nsnam/ns-3-dev.git ns-3.37

• get the satellite module (by cloning it using git);

$ cd ns-3.37/contrib
$ git clone https://github.com/sns3/sns3-satellite.git satellite

• get the traffic and magister-stats modules (needed until they are integrated into NS-3) as dependencies of the satellite module by cloning them :

$ git clone https://github.com/sns3/traffic.git traffic
$ git clone https://github.com/sns3/stats.git magister-stats

note : When retrieving the satellite, traffic and magister-stats modules, you should put them under the ns-3.37/contrib/ folder. You can do so by cloning them directly in this folder, extracting them here, copying the files afterwards or using symbolic links.

Then you need to configure CMake and ask it to build NS-3. It will automatically build all modules found in contrib:

$ cd ns-3.37
$ ./ns3 clean
$ ./ns3 configure --build-profile=optimized --enable-examples --enable-tests
$ ./ns3 build

If you want to develop in NS-3, use it in debug mode. It enables debug functionnalities but it is way more slower:

$ cd ns-3.37
$ ./ns3 clean
$ ./ns3 configure --build-profile=debug --enable-examples --enable-tests
$ ./ns3 build

You can also check CMake options to customize it at will:

$ ./ns3 --help

Once you compiled SNS-3 successfully, you will need an extra step before being able to run any simulation: download the data defining the reference scenario of the simulation.

These data are available as a separate repository and bundled as a submodule in SNS-3. You can download them afterwards in the satellite repository using:

$ cd source/ns-3.37/contrib/satellite
$ git submodule update --init --recursive

You can run the unit tests of the NS-3 distribution by running the ./test.py script:

$ ./test.py --no-build

These tests are run in parallel by NS-3. You should eventually see a report saying that:

815 of 815 tests passed (815 passed, 0 failed, 0 crashed, 0 valgrind errors)

A scenario can be launched as follows:

$ ./ns3 run <ns3-program>

If command line arguments are needed, the command becomes:

$ ./ns3 run <ns3-program> -- --arg1=value1 --arg2=value2

To list all the available command line arguments of a scenario, run:

$ ./ns3 run <ns3-program> -- --PrintHelp

If debug mode is enabled, gdb can be used:

$ ./ns3 run --gdb <ns3-program>

SNS-3 is delivered with several examples. Each one allows to demonstrate one or several functionalities of SNS-3. Statistics are generated in the data/sims/<ns3-program> folder.

The main examples are:

• sat-cbr-example.cc: Simple example with CBR traffic
• sat-regeneration-example.cc: Example to test several regeneration modes on satellite: transparent, physical, link or network. By default, all simulations use one transparent satellite
• sat-constellation-example.cc: Example with LEO and GEO satellite constellations. ISLs are used to route packets between satellites, with static routing
• sat-vhts-example.cc: Create a VHTS scenario (high throughputs and high link capacities)
• sat-iot-example.cc: Create an IoT scenario (low throughputs and low link capacities)
• sat-logon-example.cc: Use the logon functionality to log the UTs on the NCC. Traffic on return channels is not send before UT is logged
• sat-ncr-example.cc: Use NCR synchronization between UTs and GWs. UT clock is generally cheap, and need to be resynchronized periodically by the NCC to correctly schedule sending of frames on return channel
• sat-lora-example.cc: Create a scenario with Lora configuration. Lora is a LPWAN protocol developed for IoT