How to Begin Implement Network Mobility Rate in NS3

To implement and study Network Mobility Rate using NS3, we must adhere to the given structured approach. The mobility rate estimates how rapidly nodes are transfer in a network, to impact link stability, handover performance, and overall behavior of network. Let’s see how to begin implementing the Network Mobility Rate using NS3:

Steps to Begin Implement Network Mobility Rate in NS3

1. Understand Mobility Rate

In a network, mobility rate states the movement speed and trajectory of nodes. It is estimated as:

• Speed: Distance moved for each unit of time such as meters per second.
• Trajectory: Path adhered by the nodes like linear, random, or custom paths.

Mobility rate impacts by:

• Link stability: In ad-hoc or wireless sensor networks.
• Handover events: In cellular networks.

2. Set up Your Environment

Make sure that we have properly installed ns3 and working correctly. Mobility models are executed by leveraging MobilityHelper class in ns3.

3. Create the Network Topology

Example: Wireless Network

NodeContainer nodes;

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

YansWifiChannelHelper channel = YansWifiChannelHelper::Default();

YansWifiPhyHelper phy = YansWifiPhyHelper::Default();

phy.SetChannel(channel.Create());

WifiHelper wifi;

wifi.SetStandard(WIFI_PHY_STANDARD_80211n);

WifiMacHelper mac;

mac.SetType(“ns3::AdhocWifiMac”);

NetDeviceContainer devices = wifi.Install(phy, mac, nodes);

4. Assign Mobility Models

Set up node movement applying MobilityHelper.

Constant Velocity Model

Velocity model used for transferring nodes at a fixed speed:

MobilityHelper mobility;

mobility.SetMobilityModel(“ns3::ConstantVelocityMobilityModel”);

mobility.Install(nodes);

for (uint32_t i = 0; i < nodes.GetN(); ++i) {

Ptr<ConstantVelocityMobilityModel> mob = nodes.Get(i)->GetObject<ConstantVelocityMobilityModel>();

mob->SetVelocity(Vector(5.0, 0.0, 0.0)); // Speed: 5 m/s along X-axis

}

Random Waypoint Model

Random waypoint model helps to arbitrarily transfer the nodes in a restricted area:

mobility.SetPositionAllocator(“ns3::RandomRectanglePositionAllocator”,

“X”, StringValue(“ns3::UniformRandomVariable[Min=0.0|Max=100.0]”),

“Y”, StringValue(“ns3::UniformRandomVariable[Min=0.0|Max=100.0]”));

mobility.SetMobilityModel(“ns3::RandomWaypointMobilityModel”,

“Speed”, StringValue(“ns3::UniformRandomVariable[Min=1.0|Max=10.0]”), // Speed range: 1-10 m/s

“Pause”, StringValue(“ns3::ConstantRandomVariable[Constant=2.0]”),   // Pause: 2 seconds

“PositionAllocator”, PointerValue(mobility.GetPositionAllocator()));

mobility.Install(nodes);

5. Set Up the Internet Stack

Allow IP-based interaction to install the Internet stack:

InternetStackHelper stack;

stack.Install(nodes);

Ipv4AddressHelper address;

address.SetBase(“10.1.1.0”, “255.255.255.0”);

NetDeviceContainer devices = wifi.Install(phy, mac, nodes);

Ipv4InterfaceContainer interfaces = address.Assign(devices);

6. Generate Traffic

Set up applications for replicating the traffic.

Example: UDP Traffic

UdpEchoServerHelper echoServer(9);

ApplicationContainer serverApps = echoServer.Install(nodes.Get(0)); // Node 0 as the server

serverApps.Start(Seconds(1.0));

serverApps.Stop(Seconds(10.0));

UdpEchoClientHelper echoClient(interfaces.GetAddress(0), 9);

echoClient.SetAttribute(“MaxPackets”, UintegerValue(1000));

echoClient.SetAttribute(“Interval”, TimeValue(Seconds(0.01))); // 10ms interval

echoClient.SetAttribute(“PacketSize”, UintegerValue(1024));    // 1KB packets

ApplicationContainer clientApps = echoClient.Install(nodes.Get(1)); // Node 1 as the client

clientApps.Start(Seconds(2.0));

clientApps.Stop(Seconds(10.0));

7. Monitor Mobility Rate

In the course of the simulation, we need to observe the nodes’ mobility rate.

Periodic Mobility Updates

Record node locations and velocities of mobility:

void LogMobility(Ptr<Node> node) {

Ptr<MobilityModel> mob = node->GetObject<MobilityModel>();

Vector position = mob->GetPosition();

Vector velocity = mob->GetVelocity();

std::cout << “Node ” << node->GetId()

<< ” Position: (” << position.x << “, ” << position.y << “, ” << position.z << “)”

<< ” Velocity: (” << velocity.x << “, ” << velocity.y << “, ” << velocity.z << “)”

<< ” at time ” << Simulator::Now().GetSeconds() << “s\n”;

}

for (uint32_t i = 0; i < nodes.GetN(); ++i) {

Simulator::Schedule(Seconds(1.0), &LogMobility, nodes.Get(i)); // Log every 1 second

}

8. Enable Tracing

ASCII and PCAP Tracing

Facilitate traces for mobility and interaction:

AsciiTraceHelper ascii;

phy.EnableAsciiAll(ascii.CreateFileStream(“mobility_rate.tr”));

phy.EnablePcapAll(“mobility_rate”);

XML Animation Tracing

Envision node movement with the support of NetAnim:

AnimationInterface anim(“mobility_rate.xml”);

9. Visualize Results

• Transfer mobility data such as position, speed into external tools like MATLAB or Excel for graphing.
• Make use of NetAnim for envisioning the node paths.

10. Experiment with Parameters

• Speed Range: Experiment various speed ranges such as pedestrian vs. vehicular mobility.
• Pause Time: Examine the influence of pause times at network performance.
• Topology Size: Change the area size and amount of nodes.

11. Run the Simulation

Finally, we execute the simulation also examine the outcomes:

Simulator::Run();

Simulator::Destroy();

In the end, you can acquire better understanding on how to set up the environment, implement the Network Mobility Rate, visualize the outcomes and execute the simulation properly using NS3 simulation tool through the given simplified mechanism and sample coding. If you did like further refinements of this topic, we will provide it.