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How to Calculate Network SNR and SINR in omnet++

To calculate the Signal-to-Noise Ratio (SNR) and Signal-to-Interference-plus-Noise Ratio (SINR) in OMNeT++ has several steps to calculate and that is critical for measuring the quality of wireless communication links and these performance metrics support to regulate the performance of a network, as they directly impact the attainable data rates, error rates, and overall communication reliability. The below are the procedures on how to implement the SNR and SINR in OMNeT++:

Steps to Calculate SNR and SINR in OMNeT++:

  1. Set Up the Wireless Network Model:
    • Describe the wireless network topology using NED files in OMNeT++ and contains to setting up nodes with wireless interfaces and configuring the wireless channel model, considering factors like path loss, shadowing, and fading.
  2. Configure the Channel Model:
    • Use a channel model that accounts for noise and interference. The INET framework in OMNeT++ delivers the numerous models that can be used like Ieee80211Radio, Ieee80211ScalarRadioMedium, and others that support the compute of SNR and SINR.
  3. Access or Calculate Received Signal Strength (RSS):
    • The received signal strength (RSS) at a receiver is the power of the received signal and usually used to compute based on the transmission power, path loss, and any fading effects.
  4. Measure or Set Noise Power:
    • The noise power at the receiver is typically a fixed value firm by the environment and receiver features. It can be configured in the wireless channel model or computed based on the receiver’s noise figure.
  5. Calculate SNR:
    • The SNR is calculated as the ratio of the received signal power to the noise power: SNR=PsignalPnoise\text{SNR} = \frac{P_{\text{signal}}}{P_{\text{noise}}}SNR=Pnoise​Psignal​​
    • This value can be expressed in decibels (dB) using: SNR (dB)=10×log⁡10(PsignalPnoise)\text{SNR (dB)} = 10 \times \log_{10}\left(\frac{P_{\text{signal}}}{P_{\text{noise}}}\right)SNR (dB)=10×log10​(Pnoise​Psignal​​)
  6. Measure Interference Power:
    • The interference power is the sum of the power of all interfering signals received by the node and deliberates by summing the received power of signals from other transmitters in the network.
  7. Calculate SINR:
    • The SINR is calculated as the ratio of the received signal power to the sum of the interference power and noise power: SINR=PsignalPinterference+Pnoise\text{SINR}=\frac{P_{\text{signal}}}{P_{\text{interference}} + P_{\text{noise}}}SINR=Pinterference​+Pnoise​Psignal​​
    • This value can also be expressed in decibels (dB) using: SINR (dB)=10×log⁡10(PsignalPinterference+Pnoise)\text{SINR (dB)} = 10 \times \log_{10}\left(\frac{P_{\text{signal}}}{P_{\text{interference}} + P_{\text{noise}}}\right)SINR (dB)=10×log10​(Pinterference​+Pnoise​Psignal​​)

Example Implementation: SNR and SINR Calculation

The below are the sample of how to calculate SNR and SINR in OMNeT++ using the INET framework:

#include <omnetpp.h>

#include “inet/physicallayer/contract/packetlevel/IRadio.h”

#include “inet/physicallayer/contract/packetlevel/IRadioMedium.h”

#include “inet/physicallayer/common/RadioMedium.h”

using namespace omnetpp;

using namespace inet;

using namespace inet::physicallayer;

class SNRAndSINRModule : public cSimpleModule {

private:

IRadio *radio;                      // Pointer to the radio module

IRadioMedium *radioMedium;          // Pointer to the radio medium module

simsignal_t snrSignal;              // Signal to record SNR

simsignal_t sinrSignal;             // Signal to record SINR

protected:

virtual void initialize() override {

// Find the radio and radio medium modules

radio = check_and_cast<IRadio *>(getParentModule()->getSubmodule(“radio”));

radioMedium = check_and_cast<IRadioMedium *>(getModuleByPath(“radioMedium”));

// Register SNR and SINR signals

snrSignal = registerSignal(“snrSignal”);

sinrSignal = registerSignal(“sinrSignal”);

// Schedule the first SNR and SINR check

scheduleAt(simTime() + par(“checkInterval”).doubleValue(), new cMessage(“checkSNRAndSINR”));

}

virtual void handleMessage(cMessage *msg) override {

if (strcmp(msg->getName(), “checkSNRAndSINR”) == 0) {

// Calculate the received signal power (in Watts)

W receivedPower = radio->getReceptionPower(radio->getLastTransmittedSignal());

// Get the noise power from the radio medium

W noisePower = radioMedium->getBackgroundNoise();

// Calculate the SNR

double snr = receivedPower.get() / noisePower.get();

double snrDb = 10 * log10(snr);

// Calculate the interference power

W interferencePower = radioMedium->getTotalInterference(radio->getLastTransmittedSignal());

// Calculate the SINR

double sinr = receivedPower.get() / (interferencePower.get() + noisePower.get());

double sinrDb = 10 * log10(sinr);

// Emit the SNR and SINR signals

emit(snrSignal, snrDb);

emit(sinrSignal, sinrDb);

EV << “SNR: ” << snrDb << ” dB, SINR: ” << sinrDb << ” dB\n”;

// Schedule the next check

scheduleAt(simTime() + par(“checkInterval”).doubleValue(), msg);

} else {

delete msg;

}

}

};

Define_Module(SNRAndSINRModule);

Explanation:

  • SNRAndSINRModule:
    • radio: A pointer to the radio module responsible for transmitting and receiving signals.
    • radioMedium: A pointer to the radio medium module that manage the wireless channel and compute background noise and interference.
    • snrSignal and sinrSignal: Registers signals to release the calculated SNR and SINR values for logging or analysis.
  • initialize() Function:
    • Locates the radio and radio medium modules and schedules the first calculation of SNR and SINR.
  • handleMessage() Function:
    • checkSNRAndSINR: Computes the received power, noise power, interference power, and subsequently the SNR and SINR and these values are then emitted as signals and logged for analysis.
  1. Run the Simulation:
  • Compile and run OMNeT++ project. The simulation will occasionally compute and log the SNR and SINR of the wireless links.
  1. Analyse and Interpret Results:
  • The SNR and SINR values deliver the insights into the quality of wireless links. Higher SNR and SINR values designate better link quality and higher potential data rates.

Additional Considerations:

  • Dynamic Conditions: SNR and SINR can vary over time because of factors like user mobility, interference, and network load. Make certain the simulation captures these dynamics.
  • Environmental Effects: Consider environmental impacts like obstacles, fading, and shadowing in channel model, as these will impact SNR and SINR.
  • Interference Sources: SINR calculations depend on the number and strength of interfering signals. Make sure that all potential interference sources are accounted for in the simulation.

This setup will permit to calculate and evaluate the Signal-to-Noise Ratio (SNR) and Signal-to-Interference-plus-Noise Ratio (SINR) in OMNeT++ simulation that provide the insights to regulate the network performance. We will explore how the SNR-SINR clarifies within other simulation frameworks.

We offer comprehensive simulation performance insights on Network SNR and SINR utilizing the omnet++ tool. Should you desire a tailored research experience, we invite you to connect with us. Our team of experts, equipped with cutting-edge tools, stands ready to support your research endeavors. Allow us to provide you with the performance metrics you need for your project.

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