How to Calculate Network Signal to Noise ratio in Ns3

To calculate the Signal-to-Noise Ratio (SNR) in ns3, we need to configure the network topology and enable tracing for capturing the relevant metrics such as signal power and noise power at the receiver and then computing the SNR.

In Signal-to-Noise Ratio (SNR) we work on all areas so get best guidance for project performance from ns3simulation.com

Below given steps will guide on calculating the SNR in ns3.

Step-by-Step Guide to Calculate SNR in ns3

1. Set Up the Simulation Environment:
   • Make sure ns3 is installed and set up properly.
   • Include necessary modules for the simulation (e.g., WiFi, Mobility, Internet).
2. Create Network Topology:
   • Define nodes and configure the network topology.
   • Set up WiFi devices and mobility models for the nodes.
3. Enable Tracing and Metrics Collection:
   • Enable tracing to capture the relevant metrics such as signal power and noise power at the receiver.
4. Run the Simulation:
   • Execute the simulation and collect the trace data.
5. Calculate SNR:
   • Use the collected trace data to calculate the SNR.

Example Code Snippet for Calculating SNR

Here’s an example of how to set up a WiFi network, enable tracing to capture signal power and noise power, and calculate the SNR in ns3:

#include “ns3/core-module.h”

#include “ns3/network-module.h”

#include “ns3/internet-module.h”

#include “ns3/point-to-point-module.h”

#include “ns3/wifi-module.h”

#include “ns3/mobility-module.h”

#include “ns3/log.h”

#include “ns3/yans-wifi-helper.h”

using namespace ns3;

NS_LOG_COMPONENT_DEFINE (“SNRExample”);

void MonitorSnr (Ptr<OutputStreamWrapper> stream, double snr)

{

*stream->GetStream () << Simulator::Now ().GetSeconds () << “\t” << snr << std::endl;

NS_LOG_UNCOND (“SNR: ” << snr << ” dB at ” << Simulator::Now ().GetSeconds () << ” seconds.”);

}

void PhyRxTrace (Ptr<OutputStreamWrapper> stream, Ptr<const Packet> packet, double snr, WifiTxVector txVector, WifiPreamble preamble)

{

MonitorSnr (stream, 10 * std::log10 (snr));

}

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

{

// Set up logging

LogComponentEnable (“UdpClient”, LOG_LEVEL_INFO);

LogComponentEnable (“UdpServer”, LOG_LEVEL_INFO);

// Create nodes

NodeContainer wifiStaNodes;

wifiStaNodes.Create (2);

NodeContainer wifiApNode = wifiStaNodes.Get (0);

// Install WiFi

YansWifiChannelHelper channel = YansWifiChannelHelper::Default ();

YansWifiPhyHelper phy = YansWifiPhyHelper::Default ();

phy.SetChannel (channel.Create ());

WifiHelper wifi;

wifi.SetStandard (WIFI_STANDARD_80211n);

WifiMacHelper mac;

Ssid ssid = Ssid (“ns-3-ssid”);

mac.SetType (“ns3::StaWifiMac”,

“Ssid”, SsidValue (ssid),

“ActiveProbing”, BooleanValue (false));

NetDeviceContainer staDevices = wifi.Install (phy, mac, wifiStaNodes.Get (1));

mac.SetType (“ns3::ApWifiMac”,

“Ssid”, SsidValue (ssid));

NetDeviceContainer apDevices = wifi.Install (phy, mac, wifiApNode);

// Install mobility model

MobilityHelper mobility;

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

mobility.Install (wifiApNode);

mobility.Install (wifiStaNodes.Get (1));

wifiApNode->GetObject<MobilityModel> ()->SetPosition (Vector (0, 0, 0));

wifiStaNodes.Get (1)->GetObject<MobilityModel> ()->SetPosition (Vector (5, 0, 0));

// Install Internet stack

InternetStackHelper stack;

stack.Install (wifiStaNodes);

// Assign IP addresses

Ipv4AddressHelper address;

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

Ipv4InterfaceContainer staInterfaces = address.Assign (staDevices);

Ipv4InterfaceContainer apInterfaces = address.Assign (apDevices);

// Install and start applications on nodes

uint16_t port = 9;

UdpServerHelper server (port);

ApplicationContainer serverApp = server.Install (wifiStaNodes.Get (1));

serverApp.Start (Seconds (1.0));

serverApp.Stop (Seconds (10.0));

UdpClientHelper client (staInterfaces.GetAddress (0), port);

client.SetAttribute (“MaxPackets”, UintegerValue (320));

client.SetAttribute (“Interval”, TimeValue (MilliSeconds (50)));

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

ApplicationContainer clientApp = client.Install (wifiStaNodes.Get (0));

clientApp.Start (Seconds (2.0));

clientApp.Stop (Seconds (10.0));

// Enable tracing

AsciiTraceHelper ascii;

Ptr<OutputStreamWrapper> stream = ascii.CreateFileStream (“snr-trace.tr”);

phy.EnableAsciiAll (stream);

Config::Connect (“/NodeList/*/DeviceList/*/Phy/MonitorSnifferRx”, MakeBoundCallback (&PhyRxTrace, stream));

// Run the simulation

Simulator::Stop (Seconds (10.0));

Simulator::Run ();

// Clean up

Simulator::Destroy ();

return 0;

}

Explanation:

1. Setup Logging:
   • Enable logging for the UDP applications to track their activities.
2. Create Nodes:
   • Create a set of nodes representing the WiFi stations (STAs) and access points (APs).
3. Install WiFi:
   • Configure and install WiFi devices on the nodes using YansWifiChannelHelper, YansWifiPhyHelper, WifiHelper, and WifiMacHelper.
4. Install Mobility Model:
   • Assign mobility models to the nodes to simulate movement.
5. Install Internet Stack:
   • Install the Internet stack on the nodes.
6. Assign IP Addresses:
   • Assign IP addresses to the network interfaces.
7. Install Applications:
   • Install UDP server and client applications on the nodes.
8. Enable Tracing:
   • Use a callback function to trace the SNR values during packet reception.
   • Calculate and log the SNR values.
9. Run Simulation:
   • Run the simulation for the specified duration.
10. Log SNR Values:
    • The SNR values are calculated using the signal and noise power captured during packet reception.

Analyzing the Results:

• Signal-to-Noise Ratio (SNR):
  • The SNR is calculated as the ratio of signal power to noise power, expressed in decibels (dB).
  • The higher the SNR, the better the signal quality.

At last, the calculation of network signal to noise ratio in ns3 is explained very clearly in the above steps. The SNR is calculated by dividing the signal power to noise power which is in decibels for the better signal quality.