How to Implement Channel Interference Avoidance in ns3

To implement channel interference avoidance in ns3, we need to simulate a network where nodes select channels dynamically to minimize interference. This can be accomplished by using the spectrum and Wi-Fi modules provided by ns3, as well as implementing logic for channel selection based on the observed interference. Here is a quick guide to implement this.

Steps for implementation

Step 1: Set up the simulation

Make sure that ns3 is installed in the computer. If not, install it from the official ns3 website.

Step 2: Create a New Simulation Script

In the scratch directory of our ns3, we should create a simulation script. In our example, let’s create a file named channel_interference_avoidance.cc.

Step 3: Include Necessary Headers

Include all the necessary ns3 headers in our script.

#include “ns3/core-module.h”

#include “ns3/network-module.h”

#include “ns3/internet-module.h”

#include “ns3/wifi-module.h”

#include “ns3/mobility-module.h”

#include “ns3/applications-module.h”

#include “ns3/spectrum-module.h”

#include “ns3/spectrum-channel.h”

using namespace ns3;

Step 4: Define Command-Line Arguments for Parameterization

Define parameters that can be set through the command line.

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

{

uint32_t numNodes = 10;

double simTime = 10.0;

CommandLine cmd;

cmd.AddValue(“numNodes”, “Number of nodes”, numNodes);

cmd.AddValue(“simTime”, “Simulation time (seconds)”, simTime);

cmd.Parse(argc, argv);

NodeContainer nodes;

nodes.Create(numNodes);

YansWifiPhyHelper wifiPhy = YansWifiPhyHelper::Default();

YansWifiChannelHelper wifiChannel = YansWifiChannelHelper::Default();

wifiPhy.SetChannel(wifiChannel.Create());

WifiHelper wifi;

wifi.SetStandard(WIFI_STANDARD_80211n);

WifiMacHelper wifiMac;

wifiMac.SetType(“ns3::AdhocWifiMac”);

NetDeviceContainer devices = wifi.Install(wifiPhy, wifiMac, nodes);

MobilityHelper mobility;

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

mobility.Install(nodes);

InternetStackHelper stack;

stack.Install(nodes);

Ipv4AddressHelper address;

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

Ipv4InterfaceContainer interfaces = address.Assign(devices);

// Install applications

uint16_t port = 9;

OnOffHelper onoff(“ns3::UdpSocketFactory”, Address(InetSocketAddress(interfaces.GetAddress(numNodes-1), port)));

onoff.SetConstantRate(DataRate(“500kbps”));

ApplicationContainer apps = onoff.Install(nodes.Get(0));

apps.Start(Seconds(1.0));

apps.Stop(Seconds(simTime));

PacketSinkHelper sink(“ns3::UdpSocketFactory”, Address(InetSocketAddress(Ipv4Address::GetAny(), port)));

apps = sink.Install(nodes.Get(numNodes-1));

apps.Start(Seconds(0.0));

apps.Stop(Seconds(simTime));

Simulator::Stop(Seconds(simTime));

Simulator::Run();

Simulator::Destroy();

return 0;

}

Step 5: Implement Channel Interference Measurement

To include logic for measuring interference on each channel modify the script and select the best channel. we can use the SpectrumPhy and SpectrumChannel modules to measure interference.

class ChannelInterferenceApp : public Application

{

public:

ChannelInterferenceApp();

virtual ~ChannelInterferenceApp();

void Setup(Ptr<WifiNetDevice> device, Ptr<SpectrumChannel> channel);

private:

virtual void StartApplication() override;

virtual void StopApplication() override;

void MeasureInterference();

void SelectBestChannel();

Ptr<WifiNetDevice> m_device;

Ptr<SpectrumChannel> m_channel;

EventId m_measureEvent;

};

ChannelInterferenceApp::ChannelInterferenceApp() {}

ChannelInterferenceApp::~ChannelInterferenceApp() {}

void ChannelInterferenceApp::Setup(Ptr<WifiNetDevice> device, Ptr<SpectrumChannel> channel)

{

m_device = device;

m_channel = channel;

}

void ChannelInterferenceApp::StartApplication()

{

MeasureInterference();

}

void ChannelInterferenceApp::StopApplication()

{

if (m_measureEvent.IsRunning())

{

Simulator::Cancel(m_measureEvent);

}

}

void ChannelInterferenceApp::MeasureInterference()

{

// Implement logic to measure interference

// For example, you can measure the RSSI on each channel

SelectBestChannel();

m_measureEvent = Simulator::Schedule(Seconds(1.0), &ChannelInterferenceApp::MeasureInterference, this);

}

void ChannelInterferenceApp::SelectBestChannel()

{

// Implement logic to select the best channel based on measured interference

// For example, select the channel with the lowest RSSI

NS_LOG_UNCOND(“Selecting best channel based on measured interference”);

}

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

{

uint32_t numNodes = 10;

double simTime = 10.0;

CommandLine cmd;

cmd.AddValue(“numNodes”, “Number of nodes”, numNodes);

cmd.AddValue(“simTime”, “Simulation time (seconds)”, simTime);

cmd.Parse(argc, argv);

NodeContainer nodes;

nodes.Create(numNodes);

YansWifiPhyHelper wifiPhy = YansWifiPhyHelper::Default();

YansWifiChannelHelper wifiChannel = YansWifiChannelHelper::Default();

Ptr<SpectrumChannel> spectrumChannel = wifiChannel.Create()->GetObject<SpectrumChannel>();

wifiPhy.SetChannel(spectrumChannel);

WifiHelper wifi;

wifi.SetStandard(WIFI_STANDARD_80211n);

WifiMacHelper wifiMac;

wifiMac.SetType(“ns3::AdhocWifiMac”);

NetDeviceContainer devices = wifi.Install(wifiPhy, wifiMac, nodes);

MobilityHelper mobility;

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

mobility.Install(nodes);

InternetStackHelper stack;

stack.Install(nodes);

Ipv4AddressHelper address;

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

Ipv4InterfaceContainer interfaces = address.Assign(devices);

// Create and setup ChannelInterferenceApp on each node

for (uint32_t i = 0; i < numNodes; ++i)

{

Ptr<ChannelInterferenceApp> app = CreateObject<ChannelInterferenceApp>();

app->Setup(devices.Get(i)->GetObject<WifiNetDevice>(), spectrumChannel);

nodes.Get(i)->AddApplication(app);

app->SetStartTime(Seconds(0.0));

app->SetStopTime(Seconds(simTime));

}

// Install applications

uint16_t port = 9;

OnOffHelper onoff(“ns3::UdpSocketFactory”, Address(InetSocketAddress(interfaces.GetAddress(numNodes-1), port)));

onoff.SetConstantRate(DataRate(“500kbps”));

ApplicationContainer apps = onoff.Install(nodes.Get(0));

apps.Start(Seconds(1.0));

apps.Stop(Seconds(simTime));

PacketSinkHelper sink(“ns3::UdpSocketFactory”, Address(InetSocketAddress(Ipv4Address::GetAny(), port)));

apps = sink.Install(nodes.Get(numNodes-1));

apps.Start(Seconds(0.0));

apps.Stop(Seconds(simTime));

Simulator::Stop(Seconds(simTime));

Simulator::Run();

Simulator::Destroy();

return 0;

}

Step 6: Compile and Run Your Simulation

Compile your simulation script using waf.

./waf configure

./waf build

./waf –run scratch/channel_interference_avoidance

Step 7: Analyze the Output

To ensure that interference is being measured and channels are being selected, analyze the log output based on the measured interference.

Overall, we had an analysis on the implementation of channel interference avoidance using ns3 by simulating a network where nodes can dynamically select channels to minimize interference.

Explore Implementation Channel Interference Avoidance feature in ns3tool, where nodes in simulations dynamically choose channels to decrease interference. Our team of experts can assist with your projects and offer performance analysis for your research.Reach out to ns3simulation.com for best support.