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How to Implement Network Mobility in OMNeT++

To implement the network mobility in OMNeT++ has includes mimicking the movement of nodes like mobile devices in a network, permitting them to connect to various access points (APs) or base stations as they transfer. This models are necessary for learning how network performance is affected by the movement of nodes, which is especially related for wireless and mobile networks.

The following is a procedure to executing network mobility in OMNeT++ using the INET framework:

Step-by-Step Implementations:

  1. Set Up OMNeT++ and INET Framework:
  • Install OMNeT++: Make certain that OMNeT++ is installed on the system.
  • Install INET Framework: Download and install the INET framework, which offers models for wireless networking and mobility.
  1. Define the Network Topology:

Build a network topology where mobile nodes or devices can transfer and communicate with fixed nodes like access points.

Example NED File (MobileNetwork.ned):

package mynetwork;

import inet.node.inet.AccessPoint;

import inet.node.inet.StandardHost;

import inet.mobility.single.RandomWaypointMobility;

network MobileNetwork

{

parameters:

double playgroundSizeX = default(1000m); // Size of the simulation area

double playgroundSizeY = default(1000m);

submodules:

ap1: AccessPoint {

@display(“p=200,200”);

}

ap2: AccessPoint {

@display(“p=800,200”);

}

ap3: AccessPoint {

@display(“p=500,800”);

}

mobileNode: StandardHost {

@display(“p=500,500”);

wlan[0].typename = “IdealWirelessNic”; // WiFi NIC

mobility: <RandomWaypointMobility> {

@display(“p=500,600”);

initialX = uniform(0m, playgroundSizeX); // Random initial position

initialY = uniform(0m, playgroundSizeY);

speed = uniform(1mps, 10mps); // Random speed between 1 and 10 meters per second

playgroundSizeX = playgroundSizeX;

playgroundSizeY = playgroundSizeY;

}

}

connections allowunconnected:

mobileNode.wlan[0] <–> wlan[0] <–> ap1.wlan[0];

mobileNode.wlan[0] <–> wlan[0] <–> ap2.wlan[0];

mobileNode.wlan[0] <–> wlan[0] <–> ap3.wlan[0];

}

In this example:

  • ap1, ap2, ap3: Signify three WiFi Access Points.
  • mobileNode: Denotes a mobile node equipped with a Wi-Fi NIC. The node uses RandomWaypointMobility to mimic movement through the network.
  1. Configure the Mobility Model:

The RandomWaypointMobility model is a famous choice for mimicking mobility. We can configure other parameters like speed, the size of the simulation area, and waypoint selection.

Example Mobility Configuration:

[General]

network = MobileNetwork

**.mobileNode.mobility.initialX = uniform(0m, playgroundSizeX)

**.mobileNode.mobility.initialY = uniform(0m, playgroundSizeY)

**.mobileNode.mobility.speed = uniform(1mps, 10mps)

**.mobileNode.mobility.playgroundSizeX = 1000m

**.mobileNode.mobility.playgroundSizeY = 1000m

This configuration make sure that the mobile node begins at a random position and transfers at a random speed in the particular area.

  1. Simulate Packet Transmission During Mobility:

To check the mobility model, configure the mobile node to send packets to a server during moving. This setup permits to monitor how mobility affects packet transmission.

Example Traffic Configuration:

[General]

network = MobileNetwork

**.mobileNode.numApps = 1

**.mobileNode.app[0].typename = “UdpBasicApp”

**.mobileNode.app[0].destAddresses = “server”

**.mobileNode.app[0].destPort = 1234

**.mobileNode.app[0].messageLength = 1024B

**.mobileNode.app[0].sendInterval = 1s

**.server.numApps = 1

**.server.app[0].typename = “UdpSink”

**.server.app[0].localPort = 1234

This setup configures the mobile node to send UDP packets to a secure server at regular intervals while moving.

  1. Implement Handoff Management:

As the mobile node moves, it may essential to switch (handoff) from one AP to other to maintain connectivity. Executing a handoff mechanism includes observing the signal strength and moving to a stronger AP when wanted.

Example Handoff Management Logic:

void MobileNode::handleHandoff() {

double bestSignalStrength = -DBL_MAX;

cModule *bestAp = nullptr;

for (int i = 0; i < numAps; i++) {

double signalStrength = getSignalStrength(aps[i]);

if (signalStrength > bestSignalStrength) {

bestSignalStrength = signalStrength;

bestAp = aps[i];

}

}

if (bestAp && bestAp != currentAp) {

handoffTo(bestAp);

}

}

double MobileNode::getSignalStrength(cModule *ap) {

// Example function to calculate signal strength

return ap->par(“txPower”).doubleValue() – distance(mobileNode, ap);

}

void MobileNode::handoffTo(cModule *ap) {

// Logic to perform handoff

EV << “Handoff to AP: ” << ap->getName() << “\n”;

currentAp = ap;

// Update connection parameters…

}

This instance implements a basic handoff mechanism where the mobile node chooses the AP with the strongest signal.

  1. Simulate and Record Mobility and Handoff Events:

Use OMNeT++’s recording features to log handoff occurrences, packer transmission success, and mobility events.

Example Configuration for Recording Mobility Events:

[General]

network = MobileNetwork

**.mobileNode.wlan[0].mac.handoverCount.recordScalar = true

**.mobileNode.wlan[0].mac.handoverTimes.recordVector = true

This outline records the amount of handovers and the times at which they happen, which is critical for examining the impact of mobility on network performance.

  1. Run the Simulation and Analyse Results:
  • Run the Simulation: Begin the simulation and monitor the movement of the mobile node and its communications with the APs.
  • Analyse the Results: Examine the recorded mobility and handoff events, packet transmission success, and any packet loss when after the simulation.

We can use OMNeT++’s visualization devices to understand how the mobile node transfers through the network and how it switches among APs.

  1. Explore Advanced Mobility Models:

INET framework offers numerous mobility models besides RandomWaypointMobility. We can test with other models, like:

  • Linear Mobility: Nodes transfer in a straight line.
  • Circle Mobility: Nodes move in a circular path.
  • Gauss-Markov Mobility: Nodes transfer with memory, making more realistic movement patterns.
  • Traced Mobility: Nodes monitor a predefined movement pattern based on a trace file.

Example of Using Gauss-Markov Mobility:

**.mobileNode.mobility.typename = “GaussMarkovMobility”

**.mobileNode.mobility.speed = uniform(1mps, 10mps)

**.mobileNode.mobility.alpha = 0.5  # Control the memory of previous directions

  1. Document and Report Findings:

After finalizing the simulations, document the results, containing the success rate of packet transmissions, the number of handoffs, and any packet loss during mobility. It will support to knowing the effects of mobility on network performance.

In this paper, we had given more detailed step-by-step approaches, examples, and their concepts to implement the Network Mobility in OMNeT++ using INET framework. Further informations will be presented as required.

Contact omnet-manual.com for valuable insights. The experts at omnet-manual.com present distinctive topics and concepts, in addition to assistance with network comparison analysis. To facilitate the implementation of Network Mobility within the OMNeT++ tool, we will provide you with comprehensive guidance on the movement of nodes, accompanied by a concise explanation.