Visualizing Node Mobility¶

Goals¶

In wireless simulations, the movement of mobile nodes can be a crucial aspect that greatly impacts communication among them. However, visually tracking the movement can be challenging. INET provides a mobility visualizer that makes it easier to follow mobile nodes and displays properties such as speed and direction.

This showcase demonstrates the capabilities of the mobility visualizer.

INET version: 4.0

Source files location: inet/showcases/visualizer/mobility

About the Visualizer¶

In INET, the mobility of nodes can be visualized by MobilityVisualizer module (included in the network as part of IntegratedVisualizer). By default, mobility visualization is enabled; it can be disabled by setting displayMovements parameter to false.

By default, all mobilities are considered for the visualization. This selection can be narrowed with the visualizer’s moduleFilter parameter.

The visualizer has several important features:

Movement Trail: It displays a line along the recent path of movements. The trail gradually fades out as time passes. Color, trail length and other graphical properties can be changed with parameters of the visualizer.
Velocity Vector: Velocity is represented visually by an arrow. Its starting point is the node, and its direction coincides with the movement’s direction. The arrow’s length is proportional to the node’s speed.
Orientation Arc: Node orientation is represented by an arc whose size is specified by the orientationArcSize parameter. This value is the relative size of the arc compared to a full circle. The arc’s default value is 0.25, i.e. a quarter of a circle.

These features are disabled by default; they can be enabled by setting the visualizer’s displayMovementTrails, displayVelocities and displayOrientations parameters to true.

Visualizing Mobility Features¶

The following example shows how to enable mobility visualization features. The simulation can be run by choosing the VisualizingFeatures configuration from the ini file.

Three nodes of the type AdhocHost, host1, host2, and host3, are placed in the scene. They are roaming within predefined borders.

The following video has been captured from the simulation. The default settings of mobility visualization are used.

It is difficult to track the nodes because they are moving randomly and quite fast. In our next experiment, we enable movement trails, velocity vectors, and orientation arcs. We expect that nodes can be tracked easier.

# Movement trail settings
*.visualizer.*.mobilityVisualizer.displayMovementTrails = true
*.visualizer.*.mobilityVisualizer.trailLength = 300

# Velocity vector settings
*.visualizer.*.mobilityVisualizer.displayVelocities = true

# Orientation settings
*.visualizer.*.mobilityVisualizer.displayOrientations = true

The following video shows what happens when we run the simulation.

Compare this video to the previous one! The first thing you may notice is that the hosts’ movement is the same as in the previous video. However, it is now possible to see that the movement of host3 is not actually random, but rather, it moves along a circle. The host1 and host2 nodes can also be easily tracked because of the visualization.

Sources: omnetpp.ini, MobilityVisualizerShowcase.ned

More Information¶

This example only demonstrates the key features of mobility visualization. For more information, refer to the MobilityVisualizer NED documentation.

Try It Yourself¶

If you already have INET and OMNeT++ installed, start the IDE by typing omnetpp, import the INET project into the IDE, then navigate to the inet/showcases/visualizer/canvas/mobility folder in the Project Explorer. There, you can view and edit the showcase files, run simulations, and analyze results.

Otherwise, there is an easy way to install INET and OMNeT++ using opp_env, and run the simulation interactively. Ensure that opp_env is installed on your system, then execute:

$ opp_env run inet-4.0 --init -w inet-workspace --install --chdir \
   -c 'cd inet-4.0.*/showcases/visualizer/canvas/mobility && inet'

This command creates an inet-workspace directory, installs the appropriate versions of INET and OMNeT++ within it, and launches the inet command in the showcase directory for interactive simulation.

Alternatively, for a more hands-on experience, you can first set up the workspace and then open an interactive shell:

$ opp_env install --init -w inet-workspace inet-4.0
$ cd inet-workspace
$ opp_env shell

Inside the shell, start the IDE by typing omnetpp, import the INET project, then start exploring.

Discussion¶

Use this page in the GitHub issue tracker for commenting on this showcase.