How to Calculate Spectral efficiency in ns3

To calculate the spectral efficiency in ns3, whenever we want to transfer the data the spectral efficiency have provided the bandwidth to the networks. Its unit is bit per second per Hertz (bps/Hz). To compute the spectral efficiency in ns3, we need to determine the data rate and bandwidth used for the transmission. Here is the procedure on how to compute the spectral efficiency in ns3:

1. Set up Your Simulation Environment: Create a network topology; configure nodes, links, and protocols.
2. Install Applications: Set up applications on the nodes to generate and receive traffic.
3. Trace Packets and Collect Metrics: Use ns3 tracing capabilities to record the number of bits transmitted and the bandwidth used.
4. Calculate Spectral Efficiency: Divide the data rate by the bandwidth.

Example: Simple Spectral Efficiency Calculation

Here, we generate the basic network topology and determine how the spectral efficiency utilized by gathered number of bits that transferred and bandwidth used in the network.

Step 1: Set Up Your Simulation Environment

#include “ns3/core-module.h”

#include “ns3/network-module.h”

#include “ns3/internet-module.h”

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

#include “ns3/applications-module.h”

#include “ns3/flow-monitor-helper.h”

using namespace ns3;

NS_LOG_COMPONENT_DEFINE (“SpectralEfficiencyExample”);

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

{

// Create two nodes

NodeContainer nodes;

nodes.Create (2);

// Set up the point-to-point link

PointToPointHelper pointToPoint;

pointToPoint.SetDeviceAttribute (“DataRate”, StringValue (“10Mbps”));

pointToPoint.SetChannelAttribute (“Delay”, StringValue (“2ms”));

// Install link devices on nodes

NetDeviceContainer devices = pointToPoint.Install (nodes);

// Install the internet stack

InternetStackHelper stack;

stack.Install (nodes);

// Assign IP addresses

Ipv4AddressHelper address;

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

Ipv4InterfaceContainer interfaces = address.Assign (devices);

// Set up the UDP echo server on Node 1

uint16_t port = 9; // well-known echo port number

UdpEchoServerHelper echoServer (port);

ApplicationContainer serverApps = echoServer.Install (nodes.Get (1));

serverApps.Start (Seconds (1.0));

serverApps.Stop (Seconds (10.0));

// Set up the UDP echo client on Node 0

UdpEchoClientHelper echoClient (interfaces.GetAddress (1), port);

echoClient.SetAttribute (“MaxPackets”, UintegerValue (1000));

echoClient.SetAttribute (“Interval”, TimeValue (Seconds (0.01))); // 10 packets per second

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

ApplicationContainer clientApps = echoClient.Install (nodes.Get (0));

clientApps.Start (Seconds (2.0));

clientApps.Stop (Seconds (10.0));

// Enable tracing

AsciiTraceHelper ascii;

pointToPoint.EnableAsciiAll (ascii.CreateFileStream (“spectral-efficiency-example.tr”));

// Set up flow monitor

FlowMonitorHelper flowmon;

Ptr<FlowMonitor> monitor = flowmon.InstallAll();

// Run the simulation

Simulator::Run ();

// Calculate data rate and spectral efficiency

monitor->CheckForLostPackets ();

Ptr<Ipv4FlowClassifier> classifier = DynamicCast<Ipv4FlowClassifier> (flowmon.GetClassifier ());

std::map<FlowId, FlowMonitor::FlowStats> stats = monitor->GetFlowStats ();

double totalBytesReceived = 0;

double totalTime = 0;

double bandwidth = 10e6; // Bandwidth in Hz (10 Mbps)

for (std::map<FlowId, FlowMonitor::FlowStats>::const_iterator i = stats.begin (); i != stats.end (); ++i)

{

Ipv4FlowClassifier::FiveTuple t = classifier->FindFlow (i->first);

if (t.destinationPort == port)

{

totalBytesReceived += i->second.rxBytes;

totalTime+=i>second.timeLastRxPacket.GetSeconds()i>second.timeFirstTxPacket.GetSeconds ();

}

}

double dataRate = (totalBytesReceived * 8) / totalTime; // Convert bytes to bits

double spectralEfficiency = dataRate / bandwidth;

std::cout << “Total Bytes Received: ” << totalBytesReceived << ” bytes” << std::endl;

std::cout << “Total Time: ” << totalTime << ” seconds” << std::endl;

std::cout << “Data Rate: ” << dataRate << ” bps” << std::endl;

std::cout << “Spectral Efficiency: ” << spectralEfficiency << ” bps/Hz” << std::endl;

Simulator::Destroy ();

return 0;

}

Explanation

Here, we had provided the structured description to process the spectral efficiency in ns3:

1. Set Up Your Simulation Environment: Create two nodes and connect them with a point-to-point link.
2. Install Applications: Install a UDP echo server on Node 1 and a UDP echo client on Node 0. Configure the client to send a specified number of packets at a specified interval.
3. Trace Packets and Collect Metrics: Use the FlowMonitor module to collect statistics such as the number of bytes received and the time of the first and last packets.
4. Calculate Spectral Efficiency: Calculate the data rate by dividing the total number of bits received by the total time of the transmission. Then calculate the spectral efficiency by dividing the data rate by the bandwidth.

Step-by-Step Breakdown

1. Create Nodes and Links: Two nodes are created and connected with a point-to-point link with a specified data rate and delay.
2. Install Internet Stack and Applications: The Internet stack is installed on the nodes, and a UDP echo server and client are set up to generate and receive traffic.
3. Trace Packet Transmission and Reception: Use the FlowMonitor module to collect statistics such as the number of bytes received and the time of the first and last packets.
4. Calculate Data Rate: The total number of bits received is calculated by multiplying the total number of bytes by 8. The data rate is then calculated by dividing the total number of bits by the total time of the transmission.
5. Calculate Spectral Efficiency: The spectral efficiency is calculated by dividing the data rate by the bandwidth used for the transmission.

So now, we have talk about how the spectral efficiency utilized and calculated the bandwidth and throughput by use of ns3 implementation. We also offer further insight into the performance of the spectral efficiency how it evaluates in other simulation tool.

We’re working diligently to enhance networking performance analysis. Connect with us at ns3simulation.com, where we’ll assist you in calculating spectral efficiency using the ns3 tool.