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How to Implement network Traffic Offloading in ns3

To implement the network traffic offloading in ns3 has includes to generate the scenario based on the certain criteria where traffic is dynamically offloaded from one network path to another. It is very helpful for the scenarios such as offloading cellular traffic to Wi-Fi or managing the network congestion. Get best Implementation of network Traffic Offloading in ns3 from our developers we give you positive outcome.

The given below is the detailed procedure on how to implement the simple network traffic offloading scenario in ns3:

Step-by-step Implementation:

  1. Set up ns3 Environment

Make sure ns3 is installed in the computer.

  1. Create a New Simulation Script

Create a new C++ or Python script for your simulation. For this example, we will use C++.

  1. Include Necessary Headers

Include the necessary ns3 headers in your script.

#include “ns3/core-module.h”

#include “ns3/network-module.h”

#include “ns3/internet-module.h”

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

#include “ns3/wifi-module.h”

#include “ns3/mobility-module.h”

#include “ns3/applications-module.h”

4.      Define the Network Topology

Set up the basic network topology with a cellular and Wi-Fi network.

using namespace ns3;

NS_LOG_COMPONENT_DEFINE (“TrafficOffloadingExample”);

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

CommandLine cmd;

cmd.Parse (argc, argv);

// Create nodes

NodeContainer ueNodes;

ueNodes.Create (1);

NodeContainer wifiApNode;

wifiApNode.Create (1);

NodeContainer p2pNodes;

p2pNodes.Add (wifiApNode.Get (0));

p2pNodes.Create (1);

// Create point-to-point link

PointToPointHelper pointToPoint;

pointToPoint.SetDeviceAttribute (“DataRate”, StringValue (“5Mbps”));

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

NetDeviceContainer p2pDevices;

p2pDevices = pointToPoint.Install (p2pNodes);

// Set up Wi-Fi network

WifiHelper wifi;

wifi.SetStandard (WIFI_STANDARD_80211n);

YansWifiChannelHelper channel = YansWifiChannelHelper::Default ();

YansWifiPhyHelper phy = YansWifiPhyHelper::Default ();

phy.SetChannel (channel.Create ());

WifiMacHelper mac;

Ssid ssid = Ssid (“ns3-80211n”);

mac.SetType (“ns3::StaWifiMac”, “Ssid”, SsidValue (ssid));

NetDeviceContainer staDevices;

staDevices = wifi.Install (phy, mac, ueNodes);

mac.SetType (“ns3::ApWifiMac”, “Ssid”, SsidValue (ssid));

NetDeviceContainer apDevices;

apDevices = wifi.Install (phy, mac, wifiApNode);

// Install the internet stack

InternetStackHelper stack;

stack.Install (ueNodes);

stack.Install (wifiApNode);

stack.Install (p2pNodes.Get (1));

Ipv4AddressHelper address;

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

Ipv4InterfaceContainer p2pInterfaces;

p2pInterfaces = address.Assign (p2pDevices);

address.SetBase (“10.1.2.0”, “255.255.255.0”);

Ipv4InterfaceContainer wifiInterfaces;

wifiInterfaces = address.Assign (staDevices);

address.Assign (apDevices);

// Set mobility

MobilityHelper mobility;

mobility.SetPositionAllocator (“ns3::GridPositionAllocator”,

“MinX”, DoubleValue (0.0),

“MinY”, DoubleValue (0.0),

“DeltaX”, DoubleValue (5.0),

“DeltaY”, DoubleValue (10.0),

“GridWidth”, UintegerValue (3),

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

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

mobility.Install (ueNodes);

mobility.Install (wifiApNode);

// Install applications

uint16_t port = 9; // Discard port

UdpServerHelper server (port);

ApplicationContainer serverApp = server.Install (p2pNodes.Get (1));

serverApp.Start (Seconds (1.0));

serverApp.Stop (Seconds (10.0));

UdpClientHelper client (p2pInterfaces.GetAddress (1), port);

client.SetAttribute (“MaxPackets”, UintegerValue (320));

client.SetAttribute (“Interval”, TimeValue (Seconds (0.05)));

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

ApplicationContainer clientApp = client.Install (ueNodes.Get (0));

clientApp.Start (Seconds (2.0));

clientApp.Stop (Seconds (10.0));

// Setup packet sink on Wi-Fi AP to simulate traffic offloading

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

ApplicationContainer sinkApp = packetSinkHelper.Install (wifiApNode.Get (0));

sinkApp.Start (Seconds (1.0));

sinkApp.Stop (Seconds (10.0));

// Schedule offloading event

Simulator::Schedule (Seconds (5.0), &TrafficOffloading, ueNodes.Get (0), wifiInterfaces.GetAddress (0));

// Enable pcap tracing

pointToPoint.EnablePcapAll (“traffic-offloading”);

phy.EnablePcap (“wifi-ap”, apDevices.Get (0));

phy.EnablePcap (“wifi-sta”, staDevices.Get (0));

// Run simulation

Simulator::Stop (Seconds (10.0));

Simulator::Run ();

Simulator::Destroy ();

return 0;

}

5.      Define the Traffic Offloading Function

Define a function to handle traffic offloading from the cellular network to the Wi-Fi network.

void TrafficOffloading (Ptr<Node> ueNode, Ipv4Address wifiAddress) {

Ptr<Ipv4> ipv4 = ueNode->GetObject<Ipv4> ();

int32_t interface = ipv4->GetInterfaceForAddress (wifiAddress);

if (interface != -1) {

ipv4->SetMetric (interface, 1); // Set higher priority for Wi-Fi

NS_LOG_UNCOND (“Traffic offloaded to Wi-Fi”);

} else {

NS_LOG_UNCOND (“Failed to offload traffic to Wi-Fi”);

}

}

6.      Build and Run the Script

Save the script and build it using the ns-3 build system (waf).

./waf configure

./waf build

./waf –run your-script-name

Explanation

  • Network Topology: The script sets up a simple network topology with one UE (user equipment) node, a Wi-Fi AP node, and a point-to-point link to simulate a backhaul connection.
  • Wi-Fi Setup: The script sets up a Wi-Fi network with one AP and one STA (station).
  • Traffic Applications: UDP traffic is generated from the UE node to a server on the point-to-point link.
  • Traffic Offloading: A function TrafficOffloading is defined to change the route of the traffic from the cellular network to the Wi-Fi network based on certain conditions (e.g., when Wi-Fi is available). The offloading event is scheduled at 5 seconds into the simulation.
  • Packet Sink: A packet sink is installed on the Wi-Fi AP to simulate the reception of offloaded traffic.

In the final touch we should have some knowledge about how the network Traffic Offloading will perform dynamically from one path to another path in the scenarios like WiFi or manage the network congestion that were implemented by using ns3 implementation tool. We will elaborate the further helpful information about the network traffic offloading.