How to Calculate Communication Links Quality in ns3

To calculate the quality of communication links in ns3, that computes numerous metrics that specify the performance and reliability of the links among nodes. Those metrics are usually contains throughput, packet loss, delay and jitter. By track these metrics we can calculate the overall quality of communication links in the network. We also offer and provide the further information that relates to the communication quality link.

Here, we had given the step by procedures to configure the network in ns3 that executed for transmission of data, gathers relevant metrics and compute the communication link quality:

Steps to Calculate Communication Links Quality in ns3

1. Set Up ns3 Environment:
   • Make sure ns3 is installed.
2. Create a New ns3 Script:
   • Create a new script file in the scratch directory of ns3, e.g., link_quality_calculation.cc.
3. Include Necessary Headers:
   • Take in the essential ns3 headers in the script.
4. Define Network Topology:
   • Configure a network topology with multiple nodes.
5. Simulate Data Transmission:
   • Use applications to generate traffic and monitor the link performance.
6. Measure Link Quality Metrics:
   • Track metrics such as throughput, packet loss, delay, and jitter to evaluate link quality.

Example Code:

Here we had provided the sample illustrative steps that were given below:

#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/flow-monitor-module.h”

using namespace ns3;

NS_LOG_COMPONENT_DEFINE (“LinkQualityCalculationExample”);

void CalculateLinkQuality(Ptr<FlowMonitor> flowMonitor, Ptr<Ipv4FlowClassifier> classifier)

{

FlowMonitor::FlowStatsContainer stats = flowMonitor->GetFlowStats();

double totalThroughput = 0.0;

double totalPacketLoss = 0.0;

double totalDelay = 0.0;

double totalJitter = 0.0;

uint32_t totalFlows = 0;

for (auto it = stats.begin(); it != stats.end(); ++it)

{

Ipv4FlowClassifier::FiveTuple t = classifier->FindFlow(it->first);

if (t.destinationPort == 9)

{

totalThroughput += it->second.rxBytes * 8.0 / (it->second.timeLastRxPacket.GetSeconds() – it->second.timeFirstTxPacket.GetSeconds()); // bps

totalPacketLoss += it->second.txPackets – it->second.rxPackets;

totalDelay += it->second.delaySum.GetSeconds();

totalJitter += it->second.jitterSum.GetSeconds();

totalFlows++;

}

}

if (totalFlows > 0)

{

totalDelay /= totalFlows;

totalJitter /= totalFlows;

totalPacketLoss /= totalFlows;

}

std::cout << “Average Throughput: ” << totalThroughput / 1e6 << ” Mbps” << std::endl;

std::cout << “Average Packet Loss: ” << totalPacketLoss << ” packets” << std::endl;

std::cout << “Average Delay: ” << totalDelay << ” seconds” << std::endl;

std::cout << “Average Jitter: ” << totalJitter << ” seconds” << std::endl;

}

void GenerateTraffic(Ptr<Socket> socket, uint32_t pktSize, uint32_t pktCount, Time interPacketInterval)

{

if (pktCount > 0)

{

socket->Send(Create<Packet>(pktSize));

Simulator::Schedule(interPacketInterval, &GenerateTraffic, socket, pktSize, pktCount – 1, interPacketInterval);

}

}

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

{

uint32_t nNodes = 2;

double simulationTime = 10.0; // seconds

uint32_t packetSize = 1024; // bytes

uint32_t numPackets = 1000; // number of packets

Time interPacketInterval = MilliSeconds(10); // interval between packets

CommandLine cmd;

cmd.AddValue(“nNodes”, “Number of nodes”, nNodes);

cmd.AddValue(“simulationTime”, “Total simulation time”, simulationTime);

cmd.AddValue(“packetSize”, “Size of each packet”, packetSize);

cmd.AddValue(“numPackets”, “Number of packets to send”, numPackets);

cmd.AddValue(“interPacketInterval”, “Interval between packets”, interPacketInterval);

cmd.Parse(argc, argv);

NodeContainer nodes;

nodes.Create(nNodes);

PointToPointHelper pointToPoint;

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

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

NetDeviceContainer devices;

devices = pointToPoint.Install(nodes);

InternetStackHelper stack;

stack.Install(nodes);

Ipv4AddressHelper address;

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

Ipv4InterfaceContainer interfaces = address.Assign(devices);

uint16_t port = 9;

Address sinkAddress(InetSocketAddress(interfaces.GetAddress(1), port));

PacketSinkHelper packetSinkHelper(“ns3::UdpSocketFactory”, sinkAddress);

ApplicationContainer sinkApps = packetSinkHelper.Install(nodes.Get(1));

sinkApps.Start(Seconds(0.0));

sinkApps.Stop(Seconds(simulationTime));

Ptr<Socket>sourceSocket=Socket::CreateSocket(nodes.Get(0),TypeId::LookupByName(“ns3::UdpSocketFactory”));

sourceSocket->Connect(sinkAddress);

 

Simulator::ScheduleWithContext(sourceSocket->GetNode()->GetId(),Seconds(1.0), &GenerateTraffic, sourceSocket, packetSize, numPackets, interPacketInterval);

FlowMonitorHelper flowmon;

Ptr<FlowMonitor> monitor = flowmon.InstallAll();  Ptr<Ipv4FlowClassifier>classifier=DynamicCast<Ipv4FlowClassifier>(flowmon.GetClassifier());

Simulator::Stop(Seconds(simulationTime));

Simulator::Run();

CalculateLinkQuality(monitor, classifier);

Simulator::Destroy();

return 0;

}

Explanation:

At this point, we had provided the overall structure to compute the quality of communication link process in ns3:

1. Nodes and Links:
   • Created two nodes and configured a point-to-point network between them.
   • Set up the network with nodes connected using point-to-point links.
2. Applications:
   • Installed a PacketSink application on one node to simulate the receiver.
   • Created a UDP socket on another node to send packets.
3. Traffic Generation:
   • Implemented the GenerateTraffic function to send packets from the source node to the sink node at regular intervals.
4. Flow Monitor:
   • Used the FlowMonitor module to collect data on packet transmissions, including throughput, packet loss, delay, and jitter.
5. Link Quality Calculation:
   • Implemented the CalculateLinkQuality function to calculate the average throughput, packet loss, delay, and jitter based on the data collected by the FlowMonitor.
   • Printed the calculated metrics to evaluate the link quality.
6. Running the Simulation:
   • The simulation runs, sending and receiving packets.
   • After the simulation, the link quality metrics are calculated and printed.

Overall, we had calculated and simulated the communication quality links in ns3 simulation tools.

Configuration of the network in ns3 related to your project detail with best network performance are done by ns3simulation.com.