How to Begin Implement Network SNR and SINR in NS3

To begin Signal-to-Noise Ratio (SNR) and Signal-to-Interference-plus-Noise Ratio (SINR) using ns3, we can adhere to these steps. These parameters are essential to know the wireless communication channels quality. Here’s a simplified approach on how to get started with network SNR and SINR using NS3:

Steps to Begin Network SNR and SINR in NS3

1. Understand SNR and SINR

• SNR:

SNR=Signal PowerNoise Power\text{SNR} = \frac{\text{Signal Power}}{\text{Noise Power}}SNR=Noise PowerSignal Power​

• SINR:

SINR=Signal PowerInterference Power+Noise Power\text{SINR} = \frac{\text{Signal Power}}{\text{Interference Power} + \text{Noise Power}}SINR=Interference Power+Noise PowerSignal Power​

Where:

• Signal Power is the preferred signal power.
• Noise Power according to the channel and environment such as thermal noise.
• Interference Power arrives from other transmitters within the network.

2. Set Up Your Environment

We can install and download ns3 on the system. Make use of proper components such as Wi-Fi, LTE, or 5G based on the scenario.

3. Create a 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 should install the Internet stack allowed 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

To simulate traffic, we 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 SNR

Using PHY Layer Callbacks

Monitor the SNR with the support of WifiPhy:

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

std::vector<double> snrValues;

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

snrValues.push_back(snr);

std::cout << “SNR (dB): ” << snr << std::endl;

}));

Change the SNR from dB to linear scale as required:

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

7. Measure SINR

Using Interference Model

Estimate the SINR on the receiver within a multi-node network by deliberating signal power, interference power, and noise power.

1. Signal Power:

double signalPower = phy->GetTxPowerStart(); // Example signal power in dBm

signalPower = std::pow(10, signalPower / 10) / 1000; // Convert dBm to watts

1. Noise Power: It is designed for a thermal noise floor:

Noise Power=k⋅T⋅B\text{Noise Power} = k \cdot T \cdot BNoise Power=k⋅T⋅B

Where:

• k=1.38×10−23k = 1.38 \times 10^{-23}k=1.38×10−23 (Boltzmann constant in J/K).
• TTT: Temperature in Kelvin (e.g., 290K).
• BBB: Bandwidth in Hz.

double bandwidth = 20e6; // 20 MHz

double noisePower = 1.38e-23 * 290 * bandwidth; // Noise power in watts

1. Interference Power: Monitor interference power from other nodes such as interferer node:

double interferencePower = …; // Calculate based on interfering nodes

1. SINR Calculation:

double sinr = signalPower / (interferencePower + noisePower);

std::cout << “SINR: ” << sinr << ” (linear)” << std::endl;

std::cout << “SINR: ” << 10 * std::log10(sinr) << ” dB” << std::endl;

8. Analyze Results

Examine the values of SNR and SINR which are accumulated after the simulation:

• Transfer the values into external tools such as MATLAB or Excel for graphical analysis.
• Examine trends including diverse distances, interference, or traffic load.

9. Enable Tracing

ASCII and PCAP Tracing

Make comprehensive records of SNR and SINR events:

AsciiTraceHelper ascii;

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

phy.EnablePcapAll(“snr_sinr_analysis”);

10. Experiment with Parameters

• Distance: Experiment with diverse distances among the transmitter and receiver.
• Interference: Establish an interferer node to make traffic:

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));

• Modulation Scheme: Test with various PHY settings such as BPSK, QPSK.

11. Run the Simulation

Finally, execute the simulation and then monitor the outcomes:

Simulator::Run();

Simulator::Destroy();

We have illustrated the detailed implementation process for executing and examining the Network SNR and SINR using NS3 sample snippets. More advanced details regarding this topic can be added as required.