How to Implement H & off Management in OMNeT++

To implement the handover (H) and offloading (off) management using OMNeT++ has include mimicking situations where mobile nodes switch among various network access points (handover) or offload traffic from one network to other to enhance network performance. It is specifically related in mobile networks, like 5G or MANETs, where effective handover and traffic management are critical.

Steps to Implement Handover and Offloading Management in OMNeT++

1. Install OMNeT++ and INET/Simu5G Framework:
   • Make sure that OMNeT++ is installed together with the INET framework. If we are mimicking 5G networks, consider using the Simu5G framework for more comprehensive modelling.
2. Define the Network Topology:
   • Make a network topology using a .ned file that contains numerous access points (APs) or base stations (BSs) and mobile nodes (MNs). It will transfer among various network areas, activating handovers or offloading traffic.
3. Implement Handover Management:
   • Improve or use existing handover mechanisms that permit a mobile node to switch from one AP or BS to another. The decision to handover can be based on signal strength, load balancing, or other norms.
4. Implement Traffic Offloading:
   • Execute offloading mechanisms where traffic is shifted from one network like cellular to another like Wi-Fi to improve network performance. Offloading can be activated by network congestion, data type, or user preferences.
5. Simulate Various Handover and Offloading Scenarios:
   • Form scenarios where mobile nodes move among various network areas or meeting changing network conditions, triggering handover or offloading events.
6. Configure the Simulation Environment:
   • Use the .ini file to configure parameters such as mobility patterns, handover thresholds, offloading criteria, and network conditions.
7. Run the Simulation and Analyse Results:
   • Perform the simulation and analyse the performance of the handover and offloading management. Important metrics contain handover latency, packet loss during handover, load distribution, and the efficiency of traffic offloading.

Example: Implementing Basic Handover and Offloading Management in OMNeT++

1. Define the Network Topology in a .ned File

// HandoverOffloadingNetwork.ned

package networkstructure;

import inet.node.inet.WirelessHost;

import inet.node.inet.Router;

network HandoverOffloadingNetwork

{

submodules:

ap1: Router {

@display(“p=100,200”);

numApps = 1;

app[0].typename = “AccessPointApp”;

}

ap2: Router {

@display(“p=400,200”);

numApps = 1;

app[0].typename = “AccessPointApp”;

}

node: WirelessHost {

@display(“p=100,100”);

numApps = 1;

app[0].typename = “MobileNodeApp”;

}

connections:

node.wlan[0] <–> WirelessChannel <–> ap1.wlan[0];

ap1.ethg++ <–> Ethernet100m <–> ap2.ethg++;

}

2. Implement the Handover Management

Make a C++ class for the mobile node application that manages handover among access points based on signal strength or other principle.

#include <omnetpp.h>

#include <inet/applications/base/ApplicationBase.h>

using namespace omnetpp;

using namespace inet;

class MobileNodeApp : public ApplicationBase

{

protected:

virtual void initialize(int stage) override;

virtual void handleMessageWhenUp(cMessage *msg) override;

void checkHandover();

public:

virtual int numInitStages() const override { return NUM_INIT_STAGES; }

};

Define_Module(MobileNodeApp);

void MobileNodeApp::initialize(int stage)

{

ApplicationBase::initialize(stage);

if (stage == INITSTAGE_APPLICATION_LAYER) {

// Schedule periodic handover checks

scheduleAt(simTime() + 1, new cMessage(“handoverCheck”));

}

}

void MobileNodeApp::handleMessageWhenUp(cMessage *msg)

{

if (strcmp(msg->getName(), “handoverCheck”) == 0) {

checkHandover();

scheduleAt(simTime() + 1, msg);  // Re-schedule for continuous checking

} else {

delete msg;

}

}

void MobileNodeApp::checkHandover()

{

EV << “Checking if handover is needed.” << endl;

// Example: Determine if the node should handover to a different AP based on signal strength

// Placeholder logic for handover decision:

bool needHandover = uniform(0, 1) > 0.5;

if (needHandover) {

EV << “Initiating handover to another AP.” << endl;

// Implement handover logic here

// This could involve disconnecting from the current AP and connecting to another

}

}

3. Implement Traffic Offloading

We can also execute traffic offloading logic in the same MobileNodeApp class, or in a single class, where traffic is offloaded based on network conditions or data type.

void MobileNodeApp::checkOffloading()

{

EV << “Checking if traffic offloading is needed.” << endl;

// Example: Offload traffic to a different network (e.g., from cellular to Wi-Fi)

bool needOffloading = uniform(0, 1) > 0.7;

if (needOffloading) {

EV << “Offloading traffic to another network.” << endl;

// Implement offloading logic here

}

}

4. Modify Node Modules to Use the Applications

Expand the node modules to contain the applications for access points and mobile nodes.

simple Router extends inet.node.inet.Router

{

parameters:

@display(“i=device/server”);

numApps = 1;

app[0].typename = “AccessPointApp”;

}

5. Configure the Simulation in the .ini File

# omnetpp.ini

[General]

network = networkstructure.HandoverOffloadingNetwork

sim-time-limit = 200s

# Node settings

*.node.mobility.typename = “inet.mobility.single.RandomWaypointMobility”;

*.node.mobility.bounds = “500m 500m”;

*.node.wlan.mac.maxQueueSize = 1000;

*.node.wlan.phy.transmitter.power = 2mW;

*.node.app[0].handoverThreshold = -70dBm;  # Example handover threshold

*.node.app[0].offloadingThreshold = 80%;   # Example offloading threshold

6. Explanation of the Example

• Network Topology (HandoverOffloadingNetwork.ned):
  • The network contains of two access points like ap1 and ap2 and one mobile node (node). The mobile node moves in a defined area, possibly activating handovers between APs.
• Handover Management (MobileNodeApp.cc):
  • The MobileNodeApp module verifies periodically if a handover is essential based on the present network conditions like signal strength. If required, the node will switch to a various AP.
• Traffic Offloading:
  • The offloading logic can be incorporated to transferal traffic from one network to other based on thresholds such as network load or data type.
• Simulation Configuration (omnetpp.ini):
  • The .ini file configures mobility, handover thresholds, and offloading norms for the mobile node.

Running the Simulation

• Compile the project in OMNeT++ IDE and run the simulation.
• Use OMNeT++’s tools to monitor how the mobile node manages handovers among access points and how traffic is offloaded based on network conditions. Attention on metrics such as handover latency, packet loss during handover, and the efficiency of traffic offloading.

Extending the Example

• Advanced Handover Algorithms: Execute more sophisticated handover algorithms that consider various factors like QoS, user preferences, or load balancing across APs.
• Inter-Technology Offloading: Implement offloading among numerous network technologies, like from 5G to Wi-Fi or from LTE to Wi-Fi, and analyse the performance impact.
• Dynamic Traffic Patterns: Mimic several traffic patterns like streaming video, VoIP, bulk data transfer and monitor how the handover and offloading mechanisms manage these scenarios.
• Scalability Testing: Rise the number of mobile nodes and APs to check the scalability of the handover and offloading management algorithms.
• Energy-Efficient Offloading: Incorporate energy-efficient algorithms that offload traffic to keep battery life in mobile nodes while conserving network performance.

In this setup, we had shown elaborately to implement and simulate the Handover & offloading Management in OMNeT++ that contains simple approaches, some examples, and their concepts. We will deliver more specifics according to your request. If  you wish to delve deeper into H & off Management, please reach out to us. We are prepared to assist you with the most relevant topics and provide implementation support