How to Begin Implement Network Number of Handovers in NS3

To begin implementing the Network Number of Handovers within ns3, we need to follow these several steps. Handovers happen within mobile networks once a device changes from one cell (or base station) to another cell by reason of mobility or network conditions. To estimate the volume of handovers that supports for computing the network efficiency and user experience. Here’s how we can begin:

Steps to Begin Implement Network Number of Handovers in NS3

1. Understand Handovers

A handover encompasses to send a link from one access point such as eNodeB in LTE to another. It is impacted by:

• Mobility: Node movement among the cells.
• Signal Quality: Weak signal strength or interference.
• Load Balancing: To minimize congestion by delivering the users through cells.

2. Set Up Your Environment

Make sure that we have installed ns3 on the system with appropriate components for cellular interaction like LTE or mmWave.

3. Create the Network Topology

Example: LTE Network

Make numerous eNodeBs and user equipment (UE) nodes:

NodeContainer enbNodes;

enbNodes.Create(3); // Three eNodeBs

NodeContainer ueNodes;

ueNodes.Create(1); // One mobile user

MobilityHelper mobility;

mobility.SetPositionAllocator(“ns3::GridPositionAllocator”,

“MinX”, DoubleValue(0.0),

“MinY”, DoubleValue(0.0),

“DeltaX”, DoubleValue(500.0), // Distance between eNodeBs

“DeltaY”, DoubleValue(0.0),

“GridWidth”, UintegerValue(3),

“LayoutType”, StringValue(“RowFirst”));

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

mobility.Install(enbNodes);

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

mobility.Install(ueNodes);

Ptr<ConstantVelocityMobilityModel> mob = ueNodes.Get(0)->GetObject<ConstantVelocityMobilityModel>();

mob->SetVelocity(Vector(20.0, 0.0, 0.0)); // UE moving at 20 m/s along the X-axis

4. Configure the LTE Network

Configure the LTE network with eNodeBs and UE links:

Ptr<LteHelper> lteHelper = CreateObject<LteHelper>();

NetDeviceContainer enbDevs = lteHelper->InstallEnbDevice(enbNodes);

NetDeviceContainer ueDevs = lteHelper->InstallUeDevice(ueNodes);

// Attach UE to the LTE network

lteHelper->Attach(ueDevs.Get(0), enbDevs.Get(0));

5. Simulate Handover Conditions

According to the RSRP (Reference Signal Received Power) or other parameters, allow automatic handover:

lteHelper->SetHandoverAlgorithmType(“ns3::A2A4RsrqHandoverAlgorithm”);

lteHelper->SetHandoverAlgorithmAttribute(“ServingCellThreshold”, UintegerValue(30));

lteHelper->SetHandoverAlgorithmAttribute(“NeighbourCellOffset”, UintegerValue(1));

6. Track Handovers

Make use of trace callbacks to observe the handovers:

uint32_t handoverCount = 0;

void HandoverStartCallback(std::string context, uint64_t imsi, uint16_t cellId, uint16_t targetCellId) {

handoverCount++;

std::cout << “Handover started for IMSI ” << imsi

<< ” from Cell ” << cellId

<< ” to Cell ” << targetCellId

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

}

// Connect the callback

lteHelper->AddHandoverStartCallback(MakeCallback(&HandoverStartCallback));

7. Generate Traffic

Replicate the traffic, we can install applications:

ApplicationContainer serverApps;

ApplicationContainer clientApps;

UdpEchoServerHelper echoServer(9);

serverApps = echoServer.Install(ueNodes.Get(0));

serverApps.Start(Seconds(1.0));

serverApps.Stop(Seconds(10.0));

UdpEchoClientHelper echoClient(Ipv4Address(“7.0.0.1”), 9);

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

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

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

clientApps = echoClient.Install(ueNodes.Get(0));

clientApps.Start(Seconds(2.0));

clientApps.Stop(Seconds(10.0));

8. Enable Tracing

ASCII and PCAP Tracing

Record all events using ASCII and PCAP for detailed analysis:

lteHelper->EnablePhyTraces();

lteHelper->EnableMacTraces();

lteHelper->EnableRlcTraces();

lteHelper->EnablePdcpTraces();

XML Animation

Envision node movement and handovers utilising NetAnim:

AnimationInterface anim(“handover_analysis.xml”);

9. Experiment with Parameters

• Velocity: Experiment with various UE speeds for examining the handover frequency.
• Handover Algorithm: Test with diverse handover mechanisms like A3Rsrp, NoOpHandoverAlgorithm.
• Distance Between eNodeBs: Fine-tune spacing for estimating their influence over handovers.

10. Run the Simulation

Now, execute the simulation and monitor its outcomes in NS3:

Simulator::Run();

Simulator::Destroy();

11. Analyze Results

Show the total amount of handovers at the end of the simulation:

std::cout << “Total number of handovers: ” << handoverCount << std::endl;

In this manual, implementation and analysis of Network Number of Handovers have been successfully demonstrated with the support of stepwise approach and examples using NS3 simulator. Further assistance regarding this topic will be offered in another guide.