How to Calculate Network Mobility Rate in ns3

To calculate network mobility in ns3, we have to measure the rate at which nodes move within the network. The mobility rate can be described as the average speed of the nodes over the simulation period. Here is an complete guide on calculating network mobility in ns3.

Steps for calculating network mobility rate

1. Set up the simulation :

• Make sure that ns3 is installed in the computer. If not, install it and include necessary modules.

2. Create Network Topology:

• create nodes and configure the network topology.
• Set up mobility models for the nodes.

3. Install applications :

• On the nodes, setup applications to generate and receive traffic.

4. Enable tracing and Metrics Collection:

• To capture relevant metrics such as node positions and speed, use ns3 tracing capabilities.

5. Run the simulation :

• Execute the simulation and collect the trace data.

6. Analyze the results :

• Post-process the trace data to calculate the network mobility rate.

Example of a simple Network Mobility Rate

Create a basic set up of network with mobility, generate traffic, and capture metrics to calculate network Mobility Rate in ns3.

#include “ns3/core-module.h”

#include “ns3/network-module.h”

#include “ns3/internet-module.h”

#include “ns3/point-to-point-module.h”

#include “ns3/applications-module.h”

#include “ns3/mobility-module.h”

#include “ns3/log.h”

#include “ns3/config-store.h”

using namespace ns3;

NS_LOG_COMPONENT_DEFINE (“NetworkMobilityRateExample”);

std::vector<double> speeds;

void CourseChange (std::string context, Ptr<const MobilityModel> mobility)

{

Vector velocity = mobility->GetVelocity ();

double speed = std::sqrt (velocity.x * velocity.x + velocity.y * velocity.y + velocity.z * velocity.z);

speeds.push_back (speed);

}

int main (int argc, char *argv[])

{

// Set up logging

LogComponentEnable (“UdpClient”, LOG_LEVEL_INFO);

LogComponentEnable (“UdpServer”, LOG_LEVEL_INFO);

// Create nodes

NodeContainer nodes;

nodes.Create (10);

// Install Mobility model

MobilityHelper mobility;

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

mobility.Install (nodes);

// Set initial positions and velocities

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

{

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

mobility->SetPosition (Vector (i * 10, 0, 0));

mobility->SetVelocity (Vector (5.0, 0.0, 0.0)); // Set a constant speed of 5 m/s

}

// Trace course changes

Config::Connect (“/NodeList/*/$ns3::MobilityModel/CourseChange”, MakeCallback (&CourseChange));

// Install Internet stack

InternetStackHelper internet;

internet.Install (nodes);

// Assign IP addresses

PointToPointHelper p2p;

p2p.SetDeviceAttribute (“DataRate”, StringValue (“5Mbps”));

p2p.SetChannelAttribute (“Delay”, StringValue (“2ms”));

NetDeviceContainer devices;

Ipv4AddressHelper address;

Ipv4InterfaceContainer interfaces;

for (uint32_t i = 0; i < nodes.GetN () – 1; ++i)

{

NetDeviceContainer link = p2p.Install (nodes.Get (i), nodes.Get (i + 1));

devices.Add (link);

std::ostringstream subnet;

subnet << “10.1.” << i + 1 << “.0”;

address.SetBase (subnet.str ().c_str (), “255.255.255.0”);

Ipv4InterfaceContainer interface = address.Assign (link);

interfaces.Add (interface);

}

// Install and start applications on nodes

uint16_t port = 9; // Discard port (RFC 863)

UdpServerHelper server (port);

ApplicationContainer serverApp = server.Install (nodes.Get (nodes.GetN () – 1));

serverApp.Start (Seconds (1.0));

serverApp.Stop (Seconds (10.0));

UdpClientHelper client (interfaces.GetAddress (nodes.GetN () – 1), port);

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

client.SetAttribute (“Interval”, TimeValue (MilliSeconds (50)));

client.SetAttribute (“PacketSize”, UintegerValue (1024));

ApplicationContainer clientApp = client.Install (nodes.Get (0));

clientApp.Start (Seconds (2.0));

clientApp.Stop (Seconds (10.0));

// Run the simulation

Simulator::Stop (Seconds (11.0));

Simulator::Run ();

// Calculate average mobility rate

double totalSpeed = 0.0;

for (size_t i = 0; i < speeds.size (); ++i)

{

totalSpeed += speeds[i];

}

double avgSpeed = totalSpeed / speeds.size ();

NS_LOG_UNCOND (“Average Mobility Rate: ” << avgSpeed << ” m/s”);

// Clean up

Simulator::Destroy ();

return 0;

}

Explanation:

1. Setup Logging:
   • To track activities, enable logging for the UDP applications.
2. Create Nodes:
   • Create a set of nodes representing devices in the network.
3. Install Mobility Model:
   • On the nodes, install a mobility model (e.g., ConstantVelocityMobilityModel).
   • Set initial positions and velocities for the nodes.
4. Trace Course Changes:
   • To log node speed changes, connect a callback to the CourseChange trace source.
5. Install Internet Stack:
   • On the nodes, install the Internet stack.
6. Assign IP Addresses:
   • Assign IP addresses to the network interfaces.
7. Install Applications:
   • On the nodes, install UDP server and client applications.
8. Run Simulation:
   • Run the simulation for the specified duration.
9. Calculate Average Mobility Rate:
   • Calculate the average speed of the nodes, After the simulation.
   • Compute the average mobility rate as the mean of the logged speeds.

Analyzing the Results:

• Network Mobility Rate:
  • The network mobility rate is calculated as the average speed of the nodes in meters per second (m/s).
  • This metric provides an indication of the overall movement rate of the nodes in the network.

Overall, we had a performance analysis on calculating network mobility rate in ns3 by measuring the rate at which nodes move within the network. Also, we provide more detailed explanation on Network mobility rate.

Our developer’s team will present the evaluation of Network Mobility Rate in the ns3tool. Are you keen on doing a comparative network analysis, we suggest you with best results so  contact us.