How to Begin Implement Network Sampling Interval in NS3

To implement and study the Network Sampling Interval in ns-3, follow these steps. Sampling interval has the context of ns-3 commonly suggest to the periodicity by which a network parameter for instance packet delivery, delay, or energy level is tracked or logged.

Steps to Begin Implement Network Sampling Interval in NS3

1. Understand the Concept

The sampling intervals are established:

• Frequency of data collection: How frequently we collect the network statistics.
• Trade-off: The minimum sampling interval gives further granular data nevertheless are high overhead.

2. Set up Your Environment

Assure the ns3 is installed, and we are familiar by writing ns3 scripts in C++ or Python.

3. Define the Simulation Environment

As usual generate the nodes and network topology. For example:

Create Nodes:

NodeContainer nodes;

nodes.Create(2); // Two nodes for simplicity

Set Mobility:

MobilityHelper mobility;

mobility.SetPositionAllocator(“ns3::GridPositionAllocator”,

“MinX”, DoubleValue(0.0),

“MinY”, DoubleValue(0.0),

“DeltaX”, DoubleValue(50.0),

“DeltaY”, DoubleValue(0.0),

“GridWidth”, UintegerValue(3),

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

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

mobility.Install(nodes);

Add a Network Protocol:

WifiHelper wifi;

wifi.SetStandard(WIFI_PHY_STANDARD_80211n);

YansWifiPhyHelper phy = YansWifiPhyHelper::Default();

YansWifiChannelHelper channel = YansWifiChannelHelper::Default();

phy.SetChannel(channel.Create());

WifiMacHelper mac;

mac.SetType(“ns3::AdhocWifiMac”);

NetDeviceContainer devices = wifi.Install(phy, mac, nodes);

InternetStackHelper stack;

stack.Install(nodes);

Ipv4AddressHelper address;

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

Ipv4InterfaceContainer interfaces = address.Assign(devices);

4. Install Applications

Improve the applications for make the congestion:

UdpEchoServerHelper echoServer(9);

ApplicationContainer serverApps = echoServer.Install(nodes.Get(0));

serverApps.Start(Seconds(1.0));

serverApps.Stop(Seconds(10.0));

UdpEchoClientHelper echoClient(interfaces.GetAddress(0), 9);

echoClient.SetAttribute(“MaxPackets”, UintegerValue(100));

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

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

ApplicationContainer clientApps = echoClient.Install(nodes.Get(1));

clientApps.Start(Seconds(2.0));

clientApps.Stop(Seconds(10.0));

5. Define the Sampling Interval

The sampling intervals establish on how often metrics for instance packet statistics, energy levels are logged during the replication.

Example: Sampling at 1-second Intervals

void LogPacketStats(double interval) {

// Replace this with the metric you want to monitor

std::cout << “Logging at time: ” << Simulator::Now().GetSeconds() << “s” << std::endl;

// Schedule the next sampling

Simulator:: logged (Seconds(interval), &LogPacketStats, interval);

}

Schedule Initial Sampling:

double samplingInterval = 1.0; // 1-second interval

Simulator::Schedule(Seconds(samplingInterval), &LogPacketStats, samplingInterval);

6. Example Metrics to Sample

Here are track the some general metrics:

1. Throughput: Use FlowMonitorHelper to gather flow statistics.
2. Energy Levels: If using the Energy Framework, sample remaining energy.
3. Packet Delivery: Track the packets Forwarded/received using callbacks.

Example: Sampling Packet Delivery Ratio

Assign the callback for track a packets:

void PacketReceivedCallback(Ptr<const Packet> packet) {

static int receivedPackets = 0;

receivedPackets++;

std::cout << “Packets received: ” << receivedPackets << std::endl;

}

devices.Get(1)->TraceConnectWithoutContext(“PhyRxEnd”, MakeCallback(&PacketReceivedCallback));

7. Visualize Sampling Results

• Write sampled data to a file:

std::ofstream outputFile(“sampling_results.txt”);

outputFile << Simulator::Now().GetSeconds() << ” ” << receivedPackets << std::endl;

outputFile.close();

• Use tools like MATLAB or Excel for graphing.

8. Run the Simulation

Process for the replication as usual:

Simulator::Run();

Simulator::Destroy();

9. Experiment with Different Intervals

• Validate by changed intervals for sample 0.1s, 1s, 5s.
• Associate the granularity and overhead for altered a sampling interval.

10. Optimize Sampling

Deliberate the adaptive sampling:

• During increase the activity for use the minimum intervals.
• During idle periods for change the longer intervals.

From the following steps, we demonstrate information about the network sampling interval using the ns3 tool and that provides the appropriate intervals to enhance the accuracy and effectiveness.