How to Calculate Network Spectral Efficacy in Ns3

To calculate network spectral efficiency in ns3, we need to measure the efficiency of the available spectrum. The spectral efficiency generally known as data rate per unit bandwidth (e.g., bits per second per Hz). The available spectrum will transmit the data by using this efficiency.

To calculate Network Spectral Efficacy for your project, we conduct a performance analysis and explain how well the network works in practice.

Here the steps given below will guide on how to calculate the network spectral efficiency in ns3.

Step-by-Step Guide to Calculate Network Spectral Efficiency in ns3

1. Set Up the Simulation Environment:
   • Make sure ns3 is installed and set up correctly.
   • Include necessary modules for the simulation (e.g., LTE, WiFi, Internet, Mobility).
2. Create Network Topology:
   • Define nodes for the base stations (eNodeBs), access points (APs), and user equipment (UEs).
   • Set up the wireless network with appropriate configurations.
3. Configure Applications:
   • Install traffic-generating applications (e.g., UDP, TCP) on the UEs.
4. Enable Tracing and Metrics Collection:
   • Enable tracing to capture relevant metrics such as transmitted data and bandwidth usage.
5. Run the Simulation:
   • Execute the simulation and collect the trace data.
6. Analyze the Results:
   • Post-process the trace data to calculate the spectral efficiency.

Example Code Snippet for LTE Network

Here’s an example of how to set up an LTE network, generate traffic, and capture data rates to calculate spectral efficiency 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/applications-module.h”

#include “ns3/lte-module.h”

#include “ns3/epc-helper.h”

#include “ns3/mobility-module.h”

#include “ns3/flow-monitor-module.h”

#include “ns3/config-store.h”

#include “ns3/log.h”

using namespace ns3;

NS_LOG_COMPONENT_DEFINE (“LteSpectralEfficiencyExample”);

uint64_t totalDataTransmitted = 0;

double totalBandwidth = 0;

void PacketSentCallback (Ptr<const Packet> packet)

{

totalDataTransmitted += packet->GetSize();

}

void BandwidthCallback (uint32_t bandwidth)

{

totalBandwidth = bandwidth;

}

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

{

// Set up logging

LogComponentEnable (“UdpClient”, LOG_LEVEL_INFO);

LogComponentEnable (“UdpServer”, LOG_LEVEL_INFO);

// Create LTE network nodes

NodeContainer ueNodes;

NodeContainer enbNodes;

ueNodes.Create (10);

enbNodes.Create (3);

// Install Mobility model

MobilityHelper mobility;

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

mobility.Install (enbNodes);

mobility.SetPositionAllocator (“ns3::GridPositionAllocator”,

“MinX”, DoubleValue (0.0),

“MinY”, DoubleValue (0.0),

“DeltaX”, DoubleValue (50.0),

“DeltaY”, DoubleValue (50.0),

“GridWidth”, UintegerValue (3),

“LayoutType”, StringValue (“RowFirst”));

mobility.Install (ueNodes);

// Create LTE helper and EPC helper

Ptr<LteHelper> lteHelper = CreateObject<LteHelper> ();

Ptr<PointToPointEpcHelper> epcHelper = CreateObject<PointToPointEpcHelper> ();

lteHelper->SetEpcHelper (epcHelper);

// Install LTE devices to the nodes

NetDeviceContainer enbLteDevs = lteHelper->InstallEnbDevice (enbNodes);

NetDeviceContainer ueLteDevs = lteHelper->InstallUeDevice (ueNodes);

// Install Internet stack on UEs

InternetStackHelper internet;

internet.Install (ueNodes);

// Assign IP addresses to UEs

Ipv4InterfaceContainer ueIpIface;

ueIpIface = epcHelper->AssignUeIpv4Address (NetDeviceContainer (ueLteDevs));

// Attach UEs to eNodeBs

for (uint32_t i = 0; i < ueNodes.GetN (); ++i)

{

lteHelper->Attach (ueLteDevs.Get (i), enbLteDevs.Get (i % enbNodes.GetN ()));

}

// Install and start applications on UEs and remote host

uint16_t dlPort = 1234;

ApplicationContainer clientApps;

ApplicationContainer serverApps;

for (uint32_t i = 0; i < ueNodes.GetN (); ++i)

{

UdpServerHelper myServer (dlPort);

serverApps.Add (myServer.Install (ueNodes.Get (i)));

UdpClientHelper myClient (ueIpIface.GetAddress (i), dlPort);

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

myClient.SetAttribute (“Interval”, TimeValue (MilliSeconds (100)));

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

clientApps.Add (myClient.Install (ueNodes.Get (i)));

}

serverApps.Start (Seconds (1.0));

serverApps.Stop (Seconds (10.0));

clientApps.Start (Seconds (2.0));

clientApps.Stop (Seconds (10.0));

// Connect callbacks to track transmitted data

for (uint32_t i = 0; i < ueNodes.GetN (); ++i)

{

Ptr<NetDevice> netDev = ueLteDevs.Get (i);

Ptr<LteUeNetDevice> ueLteDev = DynamicCast<LteUeNetDevice> (netDev);

ueLteDev->GetPhy ()->TraceConnectWithoutContext (“PhyTxEnd”, MakeCallback (&PacketSentCallback));

}

// Run the simulation

Simulator::Stop (Seconds (11.0));

Simulator::Run ();

// Assuming bandwidth is constant and known

// Set the total bandwidth used for the LTE network

totalBandwidth = 20e6; // 20 MHz for example

// Calculate spectral efficiency

double spectralEfficiency = static_cast<double>(totalDataTransmitted) / (totalBandwidth * 10); // 10 seconds of simulation time

NS_LOG_UNCOND (“Spectral Efficiency: ” << spectralEfficiency << ” bits/s/Hz”);

// Clean up

Simulator::Destroy ();

return 0;

}

Explanation:

1. Setup Logging:
   • Enable logging for the UDP applications to track their activities.
2. Create Nodes and Network:
   • Create nodes representing UEs and eNodeBs.
   • Configure mobility models for UEs and eNodeBs.
3. Install LTE and EPC Helper:
   • Create and configure LTE and EPC helpers.
   • Install LTE devices on the UEs and eNodeBs.
4. Install Internet Stack:
   • Install the Internet stack on UEs.
   • Assign IP addresses to the UEs.
5. Attach UEs to eNodeBs:
   • Attach each UE to an eNodeB. Here, a round-robin attachment is used for simplicity.
6. Install Applications:
   • Install UDP server applications on the UEs.
   • Install UDP client applications on the UEs, sending traffic to the server.
7. Connect Callbacks to Track Transmitted Data:
   • Use PacketSentCallback to track the total amount of data transmitted.
8. Run Simulation:
   • Run the simulation for the specified duration.
9. Calculate Spectral Efficiency:
   • Calculate spectral efficiency as the ratio of total data transmitted to the product of total bandwidth and simulation time.

Spectral Efficiency=Total Data Transmitted (bits)Total Bandwidth (Hz)×Simulation Time (s)\text{Spectral Efficiency} = \frac{\text{Total Data Transmitted (bits)}}{\text{Total Bandwidth (Hz)} \times \text{Simulation Time (s)}}Spectral Efficiency=Total Bandwidth (Hz)×Simulation Time (s)Total Data Transmitted (bits)​

Analyzing the Results:

• Spectral Efficiency:
  • By dividing the total data transmitted by the product of the total bandwidth and the simulation time we had calculated the spectral efficiency.
  • This metric provides an indication of how efficiently the spectrum is utilized in the network.

The network spectral efficiency is calculated by analyzing the total transmitted data and connect callbacks to track the transmitted data.Stay in touch with ns3simulation.com for more guidance.