22. Mobility

The mobility framework in ns-3 provides support for modeling movement and position in network simulations. This system enables simulation of mobile networks, wireless protocols, and location-dependent phenomena.

The ns-3 mobility system consists of three main components:

  • Mobility Models: Track and report on the current position, velocity, and movement patterns of network nodes

  • Position Allocators: Determine initial node placement

  • Helper Classes: Simplify configuration and provide parsers for external mobility trace formats

Most mobility-related source code is located in the src/mobility directory. For building-related mobility models, see src/buildings.

The design includes mobility models, position allocators, and helper functions.

In ns-3, MobilityModel` objects track the evolution of position with respect to a (cartesian) coordinate system. The mobility model is typically aggregated to an ns3::Node object and queried using GetObject<MobilityModel> (). The base class ns3::MobilityModel is subclassed for different motion behaviors.

The initial position of objects is typically set with a PositionAllocator. These types of objects will lay out the position on a notional canvas. Once the simulation starts, the position allocator may no longer be used, or it may be used to pick future mobility “waypoints” for such mobility models.

Most users interact with the mobility system using mobility helper classes. The MobilityHelper combines a mobility model and position allocator, and can be used with a node container to install a similar mobility capability on a set of nodes.

We first describe the coordinate system and issues surrounding multiple coordinate systems.

22.1. Scope and Limitations

Current Support:

  • Cartesian, geocentric cartesian, and geographic coordinates are presently supported

  • Twelve (12) open-field mobility models and one (1) buildings aware mobility model

  • Integration with external mobility trace generators

Current Limitations:

  • Z-axis movement support varies by model

  • Limited built-in support for obstacle-aware movement

  • No native support for indoor mobility patterns

22.2. Coordinate Systems

ns-3 supports multiple coordinate systems to accommodate different simulation scenarios and real-world applications.

Cartesian Coordinates (Default):

  • Format: (x, y, z) coordinates in 3D space

  • Use case: Most suitable for simulation scenarios spanning a few kilometers

  • Implementation: ns3::Vector class represents both positions and velocities

Topocentric Coordinates:

  • Format: Cartesian coordinates with a specific Earth surface reference point

  • Use case: Converting between local and global coordinate systems

  • Implementation: Extends Cartesian with geographic origin reference (GeographicPositions::TopocentricToGeographicCoordinates in src/mobility/model/geographic-position.cc)

Geocentric Cartesian Coordinates:

  • Format: Earth-centered Cartesian system with origin at Earth’s center of mass

  • Use case: Satellite communications and global-scale simulations

  • Implementation: GeocentricConstantPositionMobilityModel

  • Reference: Follows 3GPP TR 38.811, Section 6.3 2

Geographic Coordinates:

  • Format: Latitude, longitude, and altitude relative to Earth’s surface

  • Use case: GPS-based applications and real-world location mapping

  • Implementation: GeographicPosition class with conversion utilities

At the moment, the geocentric Cartesian coordinates are adopted by the GeocentricConstantPositionMobilityModel only. This class implements the Get/SetPosition methods, which leverage the GeographicPosition class to offer conversions to and from Cartesian coordinates. Additionally, users can set the position of a node by its geographical coordinates via the methods Get/SetGeographicPosition.

22.3. Available Mobility Models

22.3.1. Core Classes

MobilityModel Base Class

The ns3::MobilityModel class is the foundation of the mobility system:

// Key methods
Vector GetPosition() const;           // Current position
Vector GetVelocity() const;          // Current velocity
double GetDistanceFrom(Ptr<const MobilityModel> other) const;

// Attributes
Vector Position;                     // Current position
Vector Velocity;                     // Current velocity

// Trace sources
TracedCallback<Ptr<const MobilityModel>> CourseChange;

Key Features:

  • Position Tracking

  • Velocity Tracking

  • Distance Calculation: Calculates distance to another mobility model object

  • Course Change Notifications: Trace source for movement events

  • Node Aggregation: Typically aggregated to ns3::Node objects

22.3.2. Child Classes

Static Models:

  • ConstantPositionMobilityModel: Nodes remain at fixed positions throughout the simulation. The position is set once during initialization and only changes if explicitly set by the user during runtime. This model is ideal for stationary infrastructure nodes, base stations, or scenarios where mobility is not required. It has near zero computational overhead during simulation runtime.

  • GeocentricConstantPositionMobilityModel: Similar to ConstantPositionMobilityModel but with geographic coordinate support. Positions can be specified using latitude, longitude, and altitude coordinates, which are internally converted to the simulation’s Cartesian coordinate system. Useful for real-world GPS-based scenarios and satellite communication simulations.

Linear Motion Models:

  • ConstantVelocityMobilityModel: Nodes move in a straight line with constant speed. The velocity vector (speed and direction) is set once and remains unchanged unless explicitly modified by external events. This model is commonly used with ns-2 mobility traces where setdest commands update the velocity.

  • ConstantAccelerationMobilityModel: Implements uniformly accelerated motion following kinematic equations. The node starts with an initial velocity and acceleration vector, with position updated according to:

\vec{p}(t) = \vec{p_0} + \vec{v_0} \cdot t + \frac{1}{2} \vec{a} \cdot t^2

This model is useful for scenarios involving vehicle acceleration/deceleration or projectile motion.

Random Motion Models:

  • RandomWalk2dMobilityModel: Implements a two-dimensional random walk where nodes change direction and speed at regular time intervals. At each step, a new direction is randomly selected from a uniform distribution [0, 2pi], and speed is drawn from a configurable random variable. Movement is constrained within specified rectangular bounds, with reflection or wrapping behavior at boundaries. The model includes configurable parameters for step time, speed distribution, and boundary behavior.

  • RandomWalk2dOutdoorMobilityModel: Enhanced version of RandomWalk2dMobilityModel that incorporates building awareness. Nodes avoid moving through building obstacles by checking for intersections with building polygons before committing to movement. When a building collision is detected, the node selects an alternative direction. This model requires integration with building models and is particularly useful for urban mobility scenarios.

  • RandomDirection2dMobilityModel: Nodes move in straight lines for random durations, then pause and select new random directions. Unlike RandomWalk2d, movement occurs in longer straight-line segments rather than frequent small steps. The model alternates between movement and pause periods, with both durations drawn from configurable random variables. Direction changes occur uniformly over [0, 2pi], and speed is constant during each movement phase.

  • RandomWaypointMobilityModel: Classic random waypoint model where nodes move from their current position to randomly selected destination waypoints. Upon reaching a waypoint, the node pauses for a random duration, then selects a new random destination. Movement between waypoints follows straight-line paths at constant speeds drawn from a configurable distribution. This model exhibits well-known characteristics including non-uniform spatial distribution and speed decay over time.

  • SteadyStateRandomWaypointMobilityModel: Addresses the initial transient behavior of the standard RandomWaypointMobilityModel by starting nodes with positions and velocities drawn from the model’s steady-state distribution. This eliminates the artificial clustering and speed artifacts present during the initial simulation phase of the standard random waypoint model, providing more realistic results from simulation start.

Advanced Models:

  • GaussMarkovMobilityModel: Implements a Gaussian-Markov stochastic process where velocity components are correlated over time. The model balances between random movement and momentum conservation using a tunable randomness parameter alpha in the range [0,1]. When alpha=0, movement is completely random; when alpha=1, movement maintains constant velocity. The velocity update equation is:

v_n = alpha \cdot v_{n-1} + (1-alpha) \cdot \bar{v} + \sqrt{1-alpha^2} \cdot v_{random}

This model produces more realistic mobility patterns with temporal correlation, suitable for human pedestrian movement.

  • WaypointMobilityModel: Follows user-defined sequences of waypoints with precise timing control. Each waypoint specifies a position and arrival time, allowing deterministic or scripted mobility patterns. The model supports complex trajectories, synchronized movement scenarios, and replay of real-world mobility traces. Waypoints can be added dynamically during simulation, enabling adaptive mobility patterns based on simulation events.

  • HierarchicalMobilityModel: Supports group mobility scenarios using parent-child relationships. Child nodes move relative to a parent mobility model, with the final position being the vector sum of parent and child positions. The parent model defines the group’s overall movement pattern, while child models define individual member movements relative to the group. This architecture enables scenarios like vehicular convoys, pedestrian groups, or mobile sensor clusters where individual nodes maintain local mobility within a moving group context.

Position Allocators:

  • ListPositionAllocator: Uses a predefined list of positions

  • GridPositionAllocator: Arranges nodes in regular grid patterns

  • RandomRectanglePositionAllocator: Uniform distribution within rectangular areas

  • RandomBoxPositionAllocator: Uniform distribution within 3D box regions

  • RandomDiscPositionAllocator: Uniform distribution within circular areas

  • UniformDiscPositionAllocator: Even distribution on disc circumference

A position allocator is not always required, as some mobility models generate initial positions during initialization. Among the built-in ns-3 models, SteadyStateRandomWaypointMobilityModel is the only one with this capability.

22.4. Helper Classes

A special mobility helper is provided that is mainly aimed at supporting the installation of mobility to a Node container (when using containers at the helper API level). The MobilityHelper class encapsulates a MobilityModel factory object and a PositionAllocator used for initial node layout.

Group mobility is also configurable via a GroupMobilityHelper object. Group mobility reuses the HierarchicalMobilityModel allowing one to define a reference (parent) mobility model and child (member) mobility models, with the position being the vector sum of the two mobility model positions (i.e., the child position is defined as an offset to the parent position). In the GroupMobilityHelper, the parent mobility model is not associated with any node, and is used as the parent mobility model for all (distinct) child mobility models. The reference point group mobility model 1 is the basis for this ns-3 model.

22.4.1. MobilityHelper

The MobilityHelper class simplifies mobility configuration:

// Basic configuration
MobilityHelper mobility;
mobility.SetPositionAllocator("ns3::GridPositionAllocator",
                              "MinX", DoubleValue(0.0),
                              "MinY", DoubleValue(0.0),
                              "DeltaX", DoubleValue(5.0),
                              "DeltaY", DoubleValue(10.0));

mobility.SetMobilityModel("ns3::RandomWalk2dMobilityModel",
                         "Bounds", RectangleValue(Rectangle(-50, 50, -50, 50)));

// Installation
mobility.Install(nodeContainer);

22.4.2. GroupMobilityHelper

Supports group mobility scenarios using the reference point group mobility model 1:

GroupMobilityHelper groupMobility;
groupMobility.SetReferencePointMobilityModel("ns3::RandomWaypointMobilityModel");
groupMobility.SetMemberMobilityModel("ns3::RandomWalk2dMobilityModel");
groupMobility.Install(groupNodes);

22.4.3. Ns2MobilityHelper

Parses ns-2 format mobility traces for compatibility with existing tools:

Ns2MobilityHelper ns2mobility("mobility-trace.ns_movements");
ns2mobility.Install();

The ns-2 mobility format is a widely used mobility trace format. Valid trace files use the following ns-2 statements:

$node set X_ x1
$node set Y_ y1
$node set Z_ z1
$ns at $time $node setdest x2 y2 speed

22.4.4. Supported ns-2 Commands

  • $node set X_ x1: Set initial X position

  • $node set Y_ y1: Set initial Y position

  • $node set Z_ z1: Set initial Z position

  • $ns at $time $node setdest x2 y2 speed: Move to destination at specified time

Note that in ns-3, movement along the Z dimension is not supported by all mobility models.

22.5. Usage

Most ns-3 program authors typically interact with the mobility system only at configuration time. However, various ns-3 objects interact with mobility objects repeatedly during runtime, such as a propagation model trying to determine the path loss between two mobile nodes.

22.5.1. Basic Configuration

22.5.1.1. Random Walk Setup

// Create nodes
NodeContainer nodes;
nodes.Create(10);

// Configure mobility
MobilityHelper mobility;

// Grid initial placement
mobility.SetPositionAllocator("ns3::GridPositionAllocator",
                              "MinX", DoubleValue(0.0),
                              "MinY", DoubleValue(0.0),
                              "DeltaX", DoubleValue(10.0),
                              "DeltaY", DoubleValue(10.0),
                              "GridWidth", UintegerValue(5),
                              "LayoutType", StringValue("RowFirst"));

// Random walk mobility
mobility.SetMobilityModel("ns3::RandomWalk2dMobilityModel",
                         "Bounds", RectangleValue(Rectangle(-100, 100, -100, 100)),
                         "Speed", StringValue("ns3::ConstantRandomVariable[Constant=5.0]"),
                         "Direction", StringValue("ns3::UniformRandomVariable[Min=0|Max=6.28]"));

mobility.Install(nodes);

22.5.1.2. Group Mobility Configuration

// Reference point group mobility
GroupMobilityHelper groupMobility;

// Parent mobility (reference point)
groupMobility.SetReferencePointMobilityModel("ns3::WaypointMobilityModel");

// Child mobility (group members)
groupMobility.SetMemberMobilityModel("ns3::RandomWalk2dMobilityModel",
                                     "Bounds", RectangleValue(Rectangle(-10, 10, -10, 10)));

// Set reference point waypoints
Ptr<WaypointMobilityModel> reference = groupMobility.GetReferencePointMobilityModel();
reference->AddWaypoint(Waypoint(Seconds(0), Vector(0, 0, 0)));
reference->AddWaypoint(Waypoint(Seconds(100), Vector(100, 0, 0)));
reference->AddWaypoint(Waypoint(Seconds(200), Vector(100, 100, 0)));

groupMobility.Install(groupNodes);

22.5.1.3. Geographic Positioning

// Use geocentric coordinates
MobilityHelper mobility;
mobility.SetMobilityModel("ns3::GeocentricConstantPositionMobilityModel");

// Set geographic position
Ptr<GeocentricConstantPositionMobilityModel> model =
    node->GetObject<GeocentricConstantPositionMobilityModel>();
model->SetGeographicPosition(Vector(latitude, longitude, altitude));

22.5.2. Advanced Usage

22.5.2.1. Random Number Stream Assignment

To avoid the possibility that configuration or parameter changes in a program affect its mobility behavior, it is necessary to assign fixed stream numbers to any random variables associated with mobility models. It is strongly advised to read the section on how to perform independent replications (see “Random Variables”, the chapter 3.1 of ns-3 Manual).

// Assign specific random streams
int64_t streamIndex = 100;
MobilityHelper mobility;
// ... configure mobility ...
mobility.Install(nodes);

// Assign streams after installation
int64_t streamsUsed = mobility.AssignStreams(nodes, streamIndex);

Class MobilityModel and class PositionAllocator both have public API to assign streams to underlying random variables:

/**
 * Assign a fixed random variable stream number to the random variables
 * used by this model. Return the number of streams (possibly zero) that
 * have been assigned.
 *
 * \param stream first stream index to use
 * \return the number of stream indices assigned by this model
 */
int64_t AssignStreams(int64_t stream);

22.5.2.2. External Tool Integration

BonnMotion

BonnMotion is a Java software which creates and analyses mobility scenarios 3 . It is developed within the Communication Systems group at the Institute of Computer Science 4 of the University of Bonn, Germany, where it serves as a tool for the investigation of mobile ad hoc network characteristics. BonnMotion is being jointly developed by the Communication Systems group at the University of Bonn, Germany, the Toilers group at the Colorado School of Mines, Golden, CO, USA, and the Distributed Systems group at the University of Osnabrück, Germany.

SUMO (Simulation of Urban Mobility)

Literature on the subject of urban wireless network often use SUMO to model the mobility in a given scenario, either based on a fictionnal setup or on real urban environment extracted through tools like OpenStreetMap.

  • Purpose: Realistic vehicular mobility simulation

  • Website: SUMO

  • Integration: Exports ns-2 format traces

  • Use Case: Urban traffic scenarios

TraNS

  • Purpose: Traffic and network simulation environment

  • Website: TraNS

  • Features: Combines SUMO with network simulation

  • Output: Compatible mobility traces

|ns2| setdest Utility

The ns-2 setdest utility can generate basic mobility patterns.

22.5.3. Tracing and Visualization

Tracing provides access to mobility models whenever the mobility model declares a course change (a change in position or velocity). Mobility models can also be polled at any time to find the current position of the model.

Course Change Tracing

An example of this tracing method is the Waypoint Mobility Model. When a node selects a new waypoint, the NotifyCourseChange() function of the MobilityModel class (parent to the WaypointMobilityModel class) is called, triggering the course change trace. This allow the user to log when an object has reached certain points.

// Enable course change logging
void CourseChangeCallback(Ptr<const MobilityModel> model) {
    Vector pos = model->GetPosition();
    Vector vel = model->GetVelocity();
    std::cout << "Node moved to: " << pos << " with velocity: " << vel << std::endl;
}

// Connect trace source
Config::Connect("/NodeList/*/$ns3::MobilityModel/CourseChange",
                MakeCallback(&CourseChangeCallback));

Mobility Model Polling

If client code needs access to a mobility model’s position or other state information outside of course change events, it may directly query the mobility model at any time. Mobility models are often aggregated (using ns-3 Object aggregation) to ns-3 nodes, so the mobility model pointer can usually be easily obtained from a node pointer using GetObject().

// Periodic position printing
void PrintPositions(NodeContainer nodes) {
    for (auto i = nodes.Begin(); i != nodes.End(); ++i) {
        Ptr<MobilityModel> mobility = (*i)->GetObject<MobilityModel>();
        Vector pos = mobility->GetPosition();
        std::cout << "Node " << (*i)->GetId() << ": " << pos << std::endl;
    }
    Simulator::Schedule(Seconds(1.0), &LogPositions, nodes);
}

22.5.4. Common Use Cases

Wireless Network Evaluation

  • Scenario: Mobile ad-hoc networks (MANETs)

  • Models: RandomWaypoint, RandomWalk2d

  • Considerations: Realistic speed distributions, pause times

Vehicular Networks

  • Scenario: Vehicle-to-vehicle (V2V) communication

  • Tools: SUMO integration

  • Models: Trace-based mobility from traffic simulators

Sensor Networks

  • Scenario: Environmental monitoring

  • Models: ConstantPosition with occasional RandomWalk

  • Considerations: Energy-efficient movement patterns

Satellite Communications

  • Scenario: Low Earth Orbit (LEO) constellations

  • Models: GeocentricConstantPosition or custom orbital models

  • Coordinates: Geocentric Cartesian system

22.6. Examples and Tests

The following example programs demonstrate mobility usage:

  • main-random-topology.cc - Random initial placement

  • main-random-walk.cc - Random walk mobility

  • main-grid-topology.cc - Grid-based positioning

  • ns2-mobility-trace.cc - ns-2 trace file parsing

  • reference-point-group-mobility-example.cc - Group mobility demonstration

22.6.1. ns2-mobility-trace Example

The ns2-mobility-trace.cc program is an example of loading an ns-2 trace file that specifies the movements of two nodes over 100 seconds of simulation time. It is paired with the file default.ns_movements.

The program behaves as follows:

  • A Ns2MobilityHelper object is created, with the specified trace file.

  • A log file is created, using the log file name argument.

  • A node container is created with the number of nodes specified in the command line. For this particular trace file, specify the value 2 for this argument.

  • The Install() method of Ns2MobilityHelper to set mobility to nodes. At this moment, the file is read line by line, and the movement is scheduled in the simulator.

  • A callback is configured, so each time a node changes its course a log message is printed.

Example usage:

$ ./ns3 run "ns2-mobility-trace \
--traceFile=src/mobility/examples/default.ns_movements \
--nodeNum=2 \
--duration=100.0 \
--logFile=ns2-mob.log"

Sample log file output:

+0.0ns POS: x=150, y=93.986, z=0; VEL:0, y=50.4038, z=0
+0.0ns POS: x=195.418, y=150, z=0; VEL:50.1186, y=0, z=0
+104727357.0ns POS: x=200.667, y=150, z=0; VEL:50.1239, y=0, z=0
+204480076.0ns POS: x=205.667, y=150, z=0; VEL:0, y=0, z=0

22.6.2. bonnmotion-ns2-example

The bonnmotion-ns2-example.cc program, which models the movement of a single mobile node for 1000 seconds of simulation time, has a few associated files:

  • bonnmotion.ns_movements is the ns-2-formatted mobility trace

  • bonnmotion.params is a BonnMotion-generated file with some metadata about the mobility trace

  • bonnmotion.ns_params is another BonnMotion-generated file with ns-2-related metadata.

Neither of the latter two files is used by ns-3, although they are generated as part of the BonnMotion process to output ns-2-compatible traces.

The program bonnmotion-ns2-example.cc will output the following to stdout:

At 0.00 node 0: Position(329.82, 66.06, 0.00);   Speed(0.53, -0.22, 0.00)
At 100.00 node 0: Position(378.38, 45.59, 0.00);   Speed(0.00, 0.00, 0.00)
At 200.00 node 0: Position(304.52, 123.66, 0.00);   Speed(-0.92, 0.97, 0.00)
At 300.00 node 0: Position(274.16, 131.67, 0.00);   Speed(-0.53, -0.46, 0.00)
At 400.00 node 0: Position(202.11, 123.60, 0.00);   Speed(-0.98, 0.35, 0.00)
At 500.00 node 0: Position(104.60, 158.95, 0.00);   Speed(-0.98, 0.35, 0.00)
At 600.00 node 0: Position(31.92, 183.87, 0.00);   Speed(0.76, -0.51, 0.00)
At 700.00 node 0: Position(107.99, 132.43, 0.00);   Speed(0.76, -0.51, 0.00)
At 800.00 node 0: Position(184.06, 80.98, 0.00);   Speed(0.76, -0.51, 0.00)
At 900.00 node 0: Position(250.08, 41.76, 0.00);   Speed(0.60, -0.05, 0.00)

The motion of the mobile node is sampled every 100 seconds, and its position and speed are printed out. This output may be compared to the output of a similar ns-2 program (found in the ns-2 tcl/ex/ directory of ns-2) running from the same mobility trace.

The next file is generated from ns-2 (users will have to download and install ns-2 and run this Tcl program to see this output). The output of the ns-2 bonnmotion-example.tcl program is shown below for comparison (file bonnmotion-example.tr):

M 0.00000 0 (329.82, 66.06, 0.00), (378.38, 45.59), 0.57
M 100.00000 0 (378.38, 45.59, 0.00), (378.38, 45.59), 0.57
M 119.37150 0 (378.38, 45.59, 0.00), (286.69, 142.52), 1.33
M 200.00000 0 (304.52, 123.66, 0.00), (286.69, 142.52), 1.33
M 276.35353 0 (286.69, 142.52, 0.00), (246.32, 107.57), 0.70
M 300.00000 0 (274.16, 131.67, 0.00), (246.32, 107.57), 0.70
M 354.65589 0 (246.32, 107.57, 0.00), (27.38, 186.94), 1.04
M 400.00000 0 (202.11, 123.60, 0.00), (27.38, 186.94), 1.04
M 500.00000 0 (104.60, 158.95, 0.00), (27.38, 186.94), 1.04
M 594.03719 0 (27.38, 186.94, 0.00), (241.02, 42.45), 0.92
M 600.00000 0 (31.92, 183.87, 0.00), (241.02, 42.45), 0.92
M 700.00000 0 (107.99, 132.43, 0.00), (241.02, 42.45), 0.92
M 800.00000 0 (184.06, 80.98, 0.00), (241.02, 42.45), 0.92
M 884.77399 0 (241.02, 42.45, 0.00), (309.59, 37.22), 0.60
M 900.00000 0 (250.08, 41.76, 0.00), (309.59, 37.22), 0.60

The output formatting is slightly different, and the course change times are additionally plotted, but it can be seen that the position vectors are the same between the two traces at intervals of 100 seconds.

The mobility computations performed on the ns-2 trace file are slightly different in ns-2 and ns-3, and floating-point arithmetic is used, so there is a chance that the position in ns-2 may be slightly different than the respective position when using the trace file in ns-3.

22.6.3. reference-point-group-mobility-example

The reference point group mobility model 1 is demonstrated in the example program reference-point-group-mobility-example.cc. This example runs a short simulation that illustrates a parent WaypointMobilityModel traversing a rectangular course within a bounding box, and three member nodes independently execute a two-dimensional random walk around the parent position, within a small bounding box.

The example illustrates configuration using the GroupMobilityHelper and manual configuration without a helper; the configuration option is selectable by command-line argument.

The example outputs two mobility trace files, a course change trace and a time-series trace of node position. The latter trace file can be parsed by a Bash script (reference-point-group-mobility-animate.sh) to create PNG images at one-second intervals, which can then be combined using an image processing program such as ImageMagick to form a basic animated gif of the mobility.

22.6.4. Tests

Specific validation results and test cases are documented in the ns-3 test suite under src/mobility/test/.

22.7. Validation

No formal validation has been done.

22.8. References

1(1,2,3)

T. Camp, J. Boleng, V. Davies. “A survey of mobility models for ad hoc network research”, in Wireless Communications and Mobile Computing, 2002: vol. 2, pp. 2483-2502.

2

3GPP. 2018. TR 38.811, Study on New Radio (NR) to support non-terrestrial networks, V15.4.0. (2020-09).

3

BonnMotion documentation, https://sys.cs.uos.de/bonnmotion/doc/README.pdf