How to Calculate Network Spectral Bandwidth in Ns3

To calculate the network spectral bandwidth in ns3, we need to measure the given communication channels bandwidth usage. In wireless networks like LTE or WiFi, Spectral bandwidth is defined as portion of frequency spectrum which is used for transmitting the data., that already predetermine by the channel configuration. We can also calculate the effective bandwidth to ensure that it is aligns with the theoretical values, which is used in the simulation process.

Here we have provided the steps to calculate Network spectral bandwidth in ns3.

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

1. Set Up the Simulation Environment:
   • Make sure ns3 is installed and setted up properly.
   • Include necessary modules for the simulation (e.g., LTE, WiFi, Internet, Mobility).
2. Create Network Topology:
   • Define nodes for the base stations (eNodeBs) 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 data rates and bandwidth usage.
5. Run the Simulation:
   • Execute the simulation and collect the trace data.
6. Calculate Spectral Bandwidth:
   • Use the collected trace data to analyze the bandwidth usage during the simulation.

Example Code Snippet for LTE Network

Here’s an example of how to set up an LTE network, generate traffic, and capture bandwidth usage 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”

using namespace ns3;

NS_LOG_COMPONENT_DEFINE (“LteSpectralBandwidthExample”);

void CalculateBandwidth (Ptr<LteEnbNetDevice> enb, Ptr<OutputStreamWrapper> stream)

{

// Get the channel bandwidth in Hz

double bandwidth = enb->GetPhy ()->GetDlBandwidth () * 180000.0; // assuming 180 kHz per resource block

*stream->GetStream () << Simulator::Now ().GetSeconds () << “\t” << bandwidth / 1e6 << ” MHz” << std::endl;

// Schedule the function to run again

Simulator::Schedule (Seconds (1.0), &CalculateBandwidth, enb, stream);

}

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));

// Create output stream for logging spectral bandwidth

AsciiTraceHelper ascii;

Ptr<OutputStreamWrapper>stream= ascii.CreateFileStream (“spectral-bandwidth-trace.txt”);

*stream->GetStream () << “Time(s)\tBandwidth(MHz)\n”;

// Connect to trace sources

Ptr<LteEnbNetDevice> enb = enbLteDevs.Get (0)->GetObject<LteEnbNetDevice> ();

Simulator::Schedule (Seconds (1.0), &CalculateBandwidth, enb, stream);

// Run the simulation

Simulator::Stop (Seconds (11.0));

Simulator::Run ();

// 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 to Trace Sources:
   • Create an output stream for logging spectral bandwidth values.
   • Connect to the trace source for calculating bandwidth.
8. Run Simulation:
   • Run the simulation for the specified duration.
9. Calculate and Log Spectral Bandwidth:
   • The CalculateBandwidth function calculates the bandwidth periodically during the simulation.
   • The bandwidth is calculated based on the number of resource blocks (RBs) allocated in LTE, where each RB is 180 kHz wide.

Analyzing the Results:

• Spectral Bandwidth:
  • The spectral bandwidth values for each eNodeB are logged along with the simulation time.
  • These metrics provide an indication of the frequency spectrum usage in the network.

The above steps provided the calculation process of Network spectral bandwidth in ns3, by measuring the bandwidth usage in communication channel and using the traffic generating applications to execute the simulation.Network Spectral Bandwidth are comparison analysis are calculated by us pertaing to your project, so share with us your parameters.