How to Calculate Network Bit Error Rate in omnet++

To calculate the Bit Error Rate (BER) in OMNeT++, we need to measure the count of bits which were received incorrectly out of the entire number of bit transferred across the network. The critical metric is BER that assess the performance of the network, especially in wireless communication system because of noise, interference or signal degradation the errors can occurs. Omnet-manual.com stands out as a premier developer, offering exceptional simulation and implementation guidance. We invite you to share the specifics of your project so that we can provide tailored assistance.

Steps to Calculate Bit Error Rate (BER) in OMNeT++:

1. Set Up the Network Model:
   • In OMNeT++, use NED files to state the network topology as well as setting up nodes and links, and simulate the realistic communication conditions like noise or interference by configuring the physical layer.
2. Introduce an Error Model:
   • During transmission, we have to simulate bit errors with the help of an error model. OMNeT++’s INET framework offers modules to simulate errors in the physical layer contains ErrorModel or NoiseSource. These models can present bit errors based on factors like signal-to-noise ratio (SNR) or other environmental conditions.
3. Track Bit Transmission and Errors:
   • Track the total number of bits transmitted and the number of erroneous bits received. This can be achieved by executing counters that increment with each transmitted and erroneous bit.
4. Calculate Bit Error Rate:
   • The BER can be calculated using the formula: BER=Number of Erroneous BitsTotal Number of Bits Transmitted\text{BER} = \frac{\text{Number of Erroneous Bits}}{\text{Total Number of Bits Transmitted}}BER=Total Number of Bits TransmittedNumber of Erroneous Bits​
   • This will give you the proportion of bits that were received incorrectly.

Example Implementation: Bit Error Rate (BER) Calculation

Here’s an example of how to calculate the BER in OMNeT++:

#include <omnetpp.h>

#include “inet/common/packet/Packet.h”

using namespace omnetpp;

using namespace inet;

class BitErrorRateModule : public cSimpleModule {

private:

int64_t totalBitsTransmitted;  // Total number of bits transmitted

int64_t erroneousBits;         // Number of bits received with errors

simsignal_t berSignal;         // Signal to record bit error rate (BER)

protected:

virtual void initialize() override {

totalBitsTransmitted = 0;

erroneousBits = 0;

berSignal = registerSignal(“berSignal”);

// Schedule the first packet transmission

scheduleAt(simTime() + par(“sendInterval”).doubleValue(), new cMessage(“sendPacket”));

}

virtual void handleMessage(cMessage *msg) override {

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

// Create and send a packet

Packet *packet = new Packet(“dataPacket”);

int packetSize = par(“packetSize”).intValue();  // in bytes

int64_t bitsTransmitted = packetSize * 8;  // Convert to bits

totalBitsTransmitted += bitsTransmitted;

// Simulate bit errors

int bitErrors = par(“bitErrorRate”).doubleValue() * bitsTransmitted;

erroneousBits += bitErrors;

send(packet, “out”)

// Schedule the next packet transmission

scheduleAt(simTime() + par(“sendInterval”).doubleValue(), new cMessage(“sendPacket”));

delete msg;

} else {

delete msg;

}

}

virtual void finish() override {

// Calculate and emit Bit Error Rate (BER)

double ber = (totalBitsTransmitted > 0) ? (double)erroneousBits / totalBitsTransmitted : 0.0;

emit(berSignal, ber);

EV << “Total Bits Transmitted: ” << totalBitsTransmitted << ” bits\n”;

EV << “Erroneous Bits: ” << erroneousBits << ” bits\n”;

EV << “Bit Error Rate (BER): ” << ber << “\n”;

}

};

Define_Module(BitErrorRateModule);

Explanation:

• BitErrorRateModule:
  • totalBitsTransmitted: Trace the total number of bits transmitted during the simulation.
  • erroneousBits: Tracks the number of bits that were received with errors.
  • berSignal: At the end of the simulation, registers a signal to emit the calculated BER at the end of the simulatin.
• initialize() Function:
  • Initializes the counters and schedules the first packet transmission.
• handleMessage() Function:
  • Manages the sending of packets and updates the counters for transmitted bits and erroneous bits. Based on the total transmitted bits, the bitErrorRate parameter simulates the proportion of bits that are erroneous.
• finish() Function:
  • At the end of the simulation, calculates the BER by dividing the number of erroneous bits by the total number of bits transmitted. The result is emitted as a signal and logged.

5. Run the Simulation:

• Compile and run OMNeT++ project. As per the simulated bit error rate and total bits transmitted, the simulation will be calculate the number of erroneous bits.

6. Analyze and Interpret Results:

• The calculated BER offers a measure of the reliability of the network in terms of bit-level accuracy. A higher BER represents a higher likelihood of errors during transmission, which can degrade overall network performance.

Additional Considerations:

• Error Models: For more realistic simulations, we can use error models from the INET framework that reflect factors like signal strength, interference, or channel conditions to dynamically estimate calculate bit errors.
• SNR and Noise: Consider simulating various signal-to-noise ratios (SNR) and noise levels to see how they impact the BER.
• Data Rate and Bandwidth: The data rate and bandwidth of the links can also impact the BER, specifically in high-speed or congested networks.

By following this steps, we can grasped the idea behind the calculation of network bit error rate and when the error occurs in the simulation process and whether it works properly or not by providing some samples in the process using OMNeT++. Additionally, by sharing your parameter details, we can help you achieve optimal results regarding Network Bit Error Rate in OMNeT++.