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How to Calculate Network Reliability in omnet++

To calculate the network reliability in OMNeT++ has needs to measure the capability of the network to successfully provide the information under fluctuating conditions that contains the possible failures of nodes or links. The term “Network reliability” is referred as to quantify in numerous ways that liable on the particular aspect of the network interested in like in the probability of effective packet delivery, the uptime of network nodes, or the robustness of the network to failures. The below are the procedures on how to calculate the network reliability in OMNeT++:

Steps to Calculate Network Reliability in OMNeT++:

  1. Define the Reliability Metric:
    • We need to measure the reliability aspects and the general parameters has contain:
      • Packet Delivery Ratio (PDR): The ratio of successfully delivered packets to the total packets sent.
      • Node/Link Uptime: The amount of time that nodes or links are operational.
      • Failure Probability: The probability that a node or link will fail during the simulation.
  2. Set Up the Network Model:
    • Describe network topology in OMNeT++ using NED files that has encompasses to setting up nodes, links, and possibly familiarizing failure models to simulate failures.
  3. Implement Traffic and Failure Models:
    • Use modules such as UdpApp, TcpApp, or custom applications to create traffic that need to introduce a failure model, where nodes or links might fail based on certain criteria like to reaching a particular energy level or encountering simulated faults.
    • This permits to emulate the real-world scenarios where the network might experience failures.
  4. Track Packet Delivery and Failures:
    • Track the number of packets sent and received to compute parameters such as  Packet Delivery Ratio (PDR).
    • Track the uptime of nodes and links to measure their reliability.
    • Monitor the occurrence of failures in the network.
  5. Calculate Reliability:
    • Depending on the metric, compute reliability using formulas such as:
      • Packet Delivery Ratio (PDR): PDR=Total Packets ReceivedTotal Packets Sent×100%\text{PDR} = \frac{\text{Total Packets Received}}{\text{Total Packets Sent}} \times 100\%PDR=Total Packets SentTotal Packets Received​×100%
      • Node/Link Uptime: Uptime=Operational TimeTotal Simulation Time×100%\text{Uptime} = \frac{\text{Operational Time}}{\text{Total Simulation Time}} \times 100\%Uptime=Total Simulation TimeOperational Time​×100%
      • Failure Rate: Failure Rate=Number of FailuresTotal Simulation Time\text{Failure Rate} = \frac{\text{Number of Failures}}{\text{Total Simulation Time}}Failure Rate=Total Simulation TimeNumber of Failures​

Example Implementation: Packet Delivery Ratio (PDR) for Reliability

The given below is an instance of how to calculate network reliability using Packet Delivery Ratio (PDR) in OMNeT++:

#include <omnetpp.h>

using namespace omnetpp;

class ReliabilityModule : public cSimpleModule {

private:

int packetsSent;

int packetsReceived;

simsignal_t pdrSignal;

protected:

virtual void initialize() override {

packetsSent = 0;

packetsReceived = 0;

pdrSignal = registerSignal(“pdrSignal”);

// Schedule the first packet send

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

}

virtual void handleMessage(cMessage *msg) override {

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

// Simulate sending a packet

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

send(packet, “out”);

packetsSent++;

// Schedule the next packet send

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

delete msg;

} else if (strcmp(msg->getName(), “dataPacket”) == 0) {

// Packet received at the destination

packetsReceived++;

delete msg;

}

}

virtual void finish() override {

// Calculate and emit Packet Delivery Ratio (PDR)

double pdr = (packetsSent > 0) ? (double)packetsReceived / packetsSent * 100.0 : 0.0;

emit(pdrSignal, pdr);

EV << “Total Packets Sent: ” << packetsSent << “\n”;

EV << “Total Packets Received: ” << packetsReceived << “\n”;

EV << “Packet Delivery Ratio (PDR): ” << pdr << ” %\n”;

}

};

Define_Module(ReliabilityModule);

Explanation:

  • initialize() Function:
    • Initializes counters for packetsSent and packetsReceived and registers a signal for emitting the Packet Delivery Ratio (PDR).
    • Schedules the first packet transmission.
  • handleMessage() Function:
    • Manage both self-messages (for sending packets) and received messages (packets).
    • Increments the packetsSent counter each time a packet is sent.
    • Increments the packetsReceived counter each time a packet is successfully received.
  • finish() Function:
    • At the end of the emulation, the function computes the PDR by dividing the number of packets received by the number of packets sent and multiplying by 100 to get a percentage.
    • The PDR is then released as a signal for analysis.
  1. Run the Simulation:
  • Compile and run OMNeT++ project. The simulation will monitor the packets sent and received that permits to compute the PDR and monitor network reliability.
  1. Analyse and Interpret Results:
  • The PDR gives an evaluation of how reliable the network is in delivering packets. A high PDR signifies high reliability, while a low PDR recommended that packets are frequently lost and that signifies the potential reliability issues.
  • If failures were emulated then measure how they impact the PDR and overall network performance.

Additional Considerations:

  • Node/Link Failures: If network has contain the possible node or link failures, we  need to monitor how these failures affect the overall network reliability by monitoring the uptime of each node or link.
  • Redundancy: Consider whether network uses redundancy that has multiple paths or backup nodes to optimize reliability, and contain this in reliability calculations.
  • Fault Tolerance: evaluate the network’s fault tolerance by emulated numerous failure scenarios and assessing the effect on reliability parameter like PDR.

Overall, we gather the information and deliver the accurate data about how to calculate the network reliability in the OMNeT++ tool and also we offer the more details on how the network reliability will calculate in other simulation tools.

We have conducted simulation performance results on Network Reliability using the OMNeT++ tool. If you’re seeking a tailored research experience, feel free to reach out to us.

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