Getting Started

Downloading and installing

Download the appropriate package (tgz or zip) from the downloads page. Uncompress the package using your favorite decompression tool. That’s it, you’ve the stack, simulator and IDE installed and ready to go!

You should have a “unetsim-1.4” folder with a structure something like this:


On Windows or Linux, there may be a few additional support folders for the IDE, and the IDE application will be called UnetIDE.exe (on Windows) or simply UnetIDE (on Linux), instead of the (on OS X) shown above.

The bin folder contains shell scripts that provide access to UnetStack and simulator framework. The etc folder contains stack configuration and initialization scripts. The samples folder contains some sample simulation scripts and agents to get you started. The logs folder should be empty now, but will eventually contain logs generated while running the stack or simulator.

Run the IDE application by double-clicking on it. The IDE should open with the default “unetsim-1.4” folder as root, and you are ready to get started. In case the default folder is different, please set the default folder to “unetsim-1.4” from the “File, Set Root Folder…” menu.


Running your first simulation

The “hello world” of the networking world is the ALOHA protocol. The protocol is simple, but it’s by no means easy to simulate. We have included an implementation in the samples/aloha folder to demonstrate how easy it is to simulate protcols with the Unet simulator. Open it in the IDE by double-clicking on aloha.groovy and run it from the “Simulation, Run” menu (or equivalently pressing the “Run simulation/script” toolbar button).


If you prefer to use a command line instead of an IDE, open a shell, change directory to the “unetsim-1.4” folder, and run the command bin/unet samples/aloha/aloha.groovy (or bin\unet samples\aloha\aloha.groovy on Windows) to run the simulation. Essentially everything that can be done from the IDE can also be done using command the unet command line tool.

If your installation is working correctly, your output should look something like this (the exact numbers may differ slightly):

Pure Aloha simulation

TX Count  RX Count  Loss %    Offered Load  Throughput
--------  --------  ------    ------------  ----------
   628       503     20.1       0.100         0.080
  1218       814     33.2       0.193         0.129
  1865      1019     45.4       0.296         0.162
  2476      1095     55.8       0.393         0.174
  3098      1145     63.0       0.492         0.182
  3801      1128     70.3       0.603         0.179
  4448      1065     76.1       0.706         0.169
  4956      1016     79.5       0.787         0.161
  5617       952     83.0       0.892         0.151
  6499       855     86.9       1.032         0.136
  6860       799     88.4       1.089         0.127
  7532       702     90.7       1.196         0.111
  8191       610     92.5       1.300         0.097
  8746       536     93.9       1.388         0.085
  9418       455     95.2       1.495         0.072

15 simulations completed in 67.510 seconds

In the unfortunate event that your output does not look like this, you may need to debug your installation. Start by checking the prerequisites. If you can’t figure out what’s wrong, you may want to head over to the support forum for help.

It’s nice to see that the simulation has run and has tabulated it’s results. As expected from the ALOHA protocol, the maximum throughput of about 0.18 is reached at an offered load of about 0.5. However, this is much nicer to see graphically. This is easily done by opening the plot-results.groovy script and running it:


As you can see, the simulation results nicely agree with the theoretical results for pure ALOHA.

Next steps

Now that you have a working installation of the Unet simulator, it’s time to learn how to develop your own protocols and simulations. The UnetStack Documentation is a good place to start. If you’re already familiar with fjåge and Groovy, you can directly move on to Developing Agents.

Developing Agents »