How to Begin Implement Network Outage probability in NS3

To begin implementing and analyzing the Network Outage Probability using ns3, we can adhere to these structured steps. Outage probability signifies the probability, which the Signal-to-Interference-plus-Noise Ratio (SINR) or achievable rate drops under a predefined threshold to show a failed or degraded connection. Here’s a basic guide on how to start and execute the Network Outage Probability in NS3:

Steps to Implement Network Outage Probability in NS3

1. Understand Outage Probability

Outage happens when:

• SINR drops under a threshold (SINRth\text{SINR}_{\text{th}}SINRth​).
• Achievable rate reduces below a needed rate like RthR_{\text{th}}Rth​.

The outage probability is offered by:

Pout=Pr⁡(SINR<SINRth)P_{\text{out}} = \Pr(\text{SINR} < \text{SINR}_{\text{th}})Pout​=Pr(SINR<SINRth​)

or

Pout=Pr⁡(R<Rth)P_{\text{out}} = \Pr(R < R_{\text{th}})Pout​=Pr(R<Rth​)

2. Set Up Your Environment

Make sure that we have installed and set up ns3 on the system. Based on the network configuration, we can leverage suitable components like Wi-Fi, LTE, or 5G.

3. Create the Network Topology

Example: Wireless Network

NodeContainer nodes;

nodes.Create(3); // One transmitter, one receiver, and one interferer

MobilityHelper mobility;

mobility.SetPositionAllocator(“ns3::GridPositionAllocator”,

“MinX”, DoubleValue(0.0),

“MinY”, DoubleValue(0.0),

“DeltaX”, DoubleValue(50.0),

“DeltaY”, DoubleValue(50.0),

“GridWidth”, UintegerValue(3),

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

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

mobility.Install(nodes);

YansWifiChannelHelper channel = YansWifiChannelHelper::Default();

YansWifiPhyHelper phy = YansWifiPhyHelper::Default();

phy.SetChannel(channel.Create());

WifiHelper wifi;

wifi.SetStandard(WIFI_PHY_STANDARD_80211n);

WifiMacHelper mac;

mac.SetType(“ns3::AdhocWifiMac”);

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

4. Set Up the Internet Stack

We can install the Internet stack for IP-based interaction:

InternetStackHelper stack;

stack.Install(nodes);

Ipv4AddressHelper address;

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

Ipv4InterfaceContainer interfaces = address.Assign(devices);

5. Generate Traffic

Replicate traffic among the nodes, we will need to install applications.

Example: UDP Traffic

UdpEchoServerHelper echoServer(9);

ApplicationContainer serverApps = echoServer.Install(nodes.Get(1)); // Receiver

serverApps.Start(Seconds(1.0));

serverApps.Stop(Seconds(10.0));

UdpEchoClientHelper echoClient(interfaces.GetAddress(1), 9);

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

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

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

ApplicationContainer clientApps = echoClient.Install(nodes.Get(0)); // Transmitter

clientApps.Start(Seconds(2.0));

clientApps.Stop(Seconds(10.0));

6. Measure SINR

Observe the values of SINR using PHY layer for the receiver.

Example: Callback for SINR

Ptr<WifiPhy> phy = DynamicCast<WifiNetDevice>(devices.Get(1))->GetPhy();

std::vector<double> sinrValues;

phy->TraceConnectWithoutContext(“Snr”, MakeCallback([&](double snr) {

double sinr = std::pow(10, snr / 10); // Convert SNR from dB to linear

sinrValues.push_back(sinr);

}));

7. Define Outage Threshold

Define a SINR or rate threshold:

double sinrThreshold = 10.0; // SINR threshold in linear scale

double rateThreshold = 1e6;  // Rate threshold in bps

8. Calculate Outage Probability

Determine the SINR’s outage probability or rate dropping below the threshold after the simulation.

Compute SINR Outage Probability

int numOutages = std::count_if(sinrValues.begin(), sinrValues.end(), [&](double sinr) {

return sinr < sinrThreshold;

});

double outageProbability = static_cast<double>(numOutages) / sinrValues.size();

std::cout << “Outage Probability (SINR): ” << outageProbability << std::endl;

Compute Rate Outage Probability

Estimate the achievable rate for each SINR:

double bandwidth = 20e6; // Bandwidth in Hz

std::vector<double> rates;

for (double sinr : sinrValues) {

double rate = bandwidth * std::log2(1 + sinr); // Shannon capacity

rates.push_back(rate);

}

numOutages = std::count_if(rates.begin(), rates.end(), [&](double rate) {

return rate < rateThreshold;

});

outageProbability = static_cast<double>(numOutages) / rates.size();

std::cout << “Outage Probability (Rate): ” << outageProbability << std::endl;

9. Enable Tracing

Packet-Level Tracing

Record all packet events relating with outages:

AsciiTraceHelper ascii;

phy.EnableAsciiAll(ascii.CreateFileStream(“outage_probability.tr”));

PCAP Tracing

Make PCAP files for in-depth analysis:

phy.EnablePcapAll(“outage_probability”);

10. Visualize Results

• Transfer probabilities of SINR and outage into a file utilising MATLAB or Excel for graphical analysis.
• Envision network events with the support of NetAnim:

AnimationInterface anim(“outage_probability.xml”);

11. Experiment with Parameters

• Modify SINR threshold and rate threshold for monitoring its effect.
• Launch interference by integrating an interferer node:

UdpEchoClientHelper interfererClient(interfaces.GetAddress(1), 9);

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

interfererClient.SetAttribute(“Interval”, TimeValue(Seconds(0.01)));

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

ApplicationContainer interfererApps = interfererClient.Install(nodes.Get(2)); // Interferer

interfererApps.Start(Seconds(2.0));

interfererApps.Stop(Seconds(10.0));

• Experiment various modulation schemes and bandwidths.

12. Run the Simulation

Execute the simulation and analyze the outcomes:

Simulator::Run();

Simulator::Destroy();

We had explained the entire implementation process with sample snippets to execute and examine the Network Outage Probability utilising NS3 tool. We are ready to offer more depth insights for advanced understanding.