How to Begin Implement Network Blockage probability in ns3

To implement and analyze Network Blockage Probability in ns-3, follow these steps. Network blockage probability suggests for the likelihood which communication path is congested or unobtainable because of physical obstacles, interference, or channel environments.

Steps to Begin Implement Network Blockage probability in ns3

1. Understand Network Blockage Probability

Network blockage occurs when:

• The line-of-sight (LoS) path is congested.
• Signal strength is falls under the usable threshold due to fading or intrusion.
• Connections are setting the fails because of network congestion or resource unavailability.

The blockage probability is designed as:

Pblockage=Number of Blocked PathsTotal Number of Transmission AttemptsP_{\text{blockage}} = \frac{\text{Number of Blocked Paths}}{\text{Total Number of Transmission Attempts}}Pblockage​=Total Number of Transmission AttemptsNumber of Blocked Paths​

2. Set up Your Environment

Assure the tool ns3 is installed and setting. Use the mmWave, LTE, or Wi-Fi components reliant on the use case. Intended for physical blockage, we want to need the incorporate the realistic mobility or obstacle patterns.

3. Create a Network Topology

Example: Wireless Network

NodeContainer nodes;

nodes.Create(3); // One transmitter, one receiver, and one potential blocker (obstacle or 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

Download the Internet stack for IP-based communication:

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

Install applications for replicate the congestion.

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. Simulate Blockage

6.1 Physical Blockage

The patterns are moving or stationary obstacle among the transmitter and receiver:

MobilityHelper obstacleMobility;

obstacleMobility.SetPositionAllocator(“ns3::GridPositionAllocator”,

“MinX”, DoubleValue(25.0), // Midway between TX and RX

“MinY”, DoubleValue(25.0));

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

obstacleMobility.Install(nodes.Get(2)); // Obstacle

6.2 Signal Blockage

Launch the path loss design for replicate the blockage impact:

Ptr<YansWifiChannel> wifiChannel = DynamicCast<YansWifiChannel>(phy.GetChannel());

wifiChannel->SetPropagationLossModel(CreateObject<ObstaclePropagationLossModel>());

Ptr<ObstaclePropagationLossModel> obstacleLoss = DynamicCast<ObstaclePropagationLossModel>(wifiChannel->GetPropagationLossModel());

obstacleLoss->SetAttribute(“BlockageLoss”, DoubleValue(30.0)); // 30 dB loss due to obstacle

7. Track Blockage Events

Monitor Successful and Blocked Packets

Monitor the packet has successfully transmitted in the lost because of blockage:

uint32_t packetsBlocked = 0;

uint32_t packetsSent = 0;

void PacketSentCallback(Ptr<const Packet> packet) {

packetsSent++;

}

void PacketBlockedCallback(Ptr<const Packet> packet) {

packetsBlocked++;

}

devices.Get(0)->TraceConnectWithoutContext(“MacTx”, MakeCallback(&PacketSentCallback));

phy->TraceConnectWithoutContext(“PhyRxDrop”, MakeCallback(&PacketBlockedCallback));

8. Calculate Blockage Probability

At the end for the replication, calculate the blockage probability:

Simulator::Schedule(Seconds(10.0), [] {

double blockageProbability = static_cast<double>(packetsBlocked) / packetsSent * 100.0;

std::cout << “Packets Sent: ” << packetsSent << std::endl;

std::cout << “Packets Blocked: ” << packetsBlocked << std::endl;

std::cout << “Blockage Probability: ” << blockageProbability << “%” << std::endl;

});

9. Enable Tracing

ASCII and PCAP Tracing

Build a log for blockage actions:

AsciiTraceHelper ascii;

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

phy.EnablePcapAll(“blockage_probability”);

10. Visualize Results

• NetAnim: Envision for action the nodes and obstacles:

AnimationInterface anim(“blockage_probability.xml”);

• Distribute the blockage data for analysis in MATLAB or Excel.

11. Experiment with Parameters

• Obstacle Mobility: It replicates the moving obstacles for follow the dynamic blockage.
• Distance: Increase the distance among transmitter and receiver for estimate the blockage of effects.
• Path Loss Models: Various design use such as Rayleigh or Rician fading for realistic blockage environment.

12. Run the Simulation

Execute the outcomes and analyze:

Simulator::Run();

Simulator::Destroy();

Finally, Network Blockage probability is measured by evaluating the of blocked connection requests to the total connection requests over a period of time and it handles connection tries under fluctuating conditions.