How to Implement Network offloading in ns3

To implement the network offloading in ns3 has includes to setup the scenario where the traffic can be redirected from a primary network like LTE to a secondary network like Wi-Fi that is to manage the load or enhance the performance.

Here, we detailed demonstrate the procedures on how to implement network offloading in ns3, elaborated how to offload the traffic from LTE to Wi-Fi.

Steps-by-Step Implementation:

Step 1: Set Up the Simulation Environment

• Make sure ns3 is installed on the computer along with required modules for Wi-Fi and LTE.

Step 2: Create the Network Topology

• Generate the simple network topology using ns3 with LTE and Wi-Fi nodes.

Step 3: Write the Script

• Here, are the complete samples on how to generate and manage the network topology in ns3 with network offloading:

1. Create a New File:
   • Save the following script as network-offloading.cc in the scratch directory of your ns-3 installation.

#include “ns3/core-module.h”

#include “ns3/network-module.h”

#include “ns3/internet-module.h”

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

#include “ns3/mobility-module.h”

#include “ns3/applications-module.h”

#include “ns3/wifi-module.h”

#include “ns3/lte-module.h”

#include “ns3/epc-helper.h”

using namespace ns3;

NS_LOG_COMPONENT_DEFINE (“NetworkOffloadingExample”);

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

{

CommandLine cmd;

cmd.Parse (argc, argv);

// Create nodes

NodeContainer ueNodes;

ueNodes.Create (1);

NodeContainer enbNodes;

enbNodes.Create (1);

NodeContainer wifiApNode;

wifiApNode.Create (1);

NodeContainer remoteHostContainer;

remoteHostContainer.Create (1);

Ptr<Node> remoteHost = remoteHostContainer.Get (0);

// Set up LTE network

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

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

lteHelper->SetEpcHelper (epcHelper);

Ptr<Node> pgw = epcHelper->GetPgwNode ();

InternetStackHelper internet;

internet.Install (remoteHostContainer);

// Create the Internet

PointToPointHelper p2ph;

p2ph.SetDeviceAttribute (“DataRate”, DataRateValue (DataRate (“100Gbps”)));

p2ph.SetChannelAttribute (“Delay”, TimeValue (MilliSeconds (1)));

NetDeviceContainer internetDevices = p2ph.Install (pgw, remoteHost);

Ipv4AddressHelper ipv4h;

ipv4h.SetBase (“1.0.0.0”, “255.0.0.0”);

Ipv4InterfaceContainer internetIpIfaces = ipv4h.Assign (internetDevices);

Ipv4Address remoteHostAddr = internetIpIfaces.GetAddress (1);

// Install LTE devices to the nodes

NetDeviceContainer enbLteDevs = lteHelper->InstallEnbDevice (enbNodes);

NetDeviceContainer ueLteDevs = lteHelper->InstallUeDevice (ueNodes);

// Install the IP stack on the UEs

internet.Install (ueNodes);

Ipv4InterfaceContainer ueIpIface;

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

// Attach the UE to the LTE network

lteHelper->Attach (ueLteDevs, enbLteDevs.Get (0));

// Set up Wi-Fi network

WifiHelper wifi;

wifi.SetRemoteStationManager (“ns3::AarfWifiManager”);

YansWifiPhyHelper wifiPhy = YansWifiPhyHelper::Default ();

YansWifiChannelHelper wifiChannel = YansWifiChannelHelper::Default ();

wifiPhy.SetChannel (wifiChannel.Create ());

WifiMacHelper wifiMac;

Ssid ssid = Ssid (“ns-3-ssid”);

wifiMac.SetType (“ns3::StaWifiMac”,

“Ssid”, SsidValue (ssid),

“ActiveProbing”, BooleanValue (false));

NetDeviceContainer staDevices = wifi.Install (wifiPhy, wifiMac, ueNodes);

wifiMac.SetType (“ns3::ApWifiMac”,

“Ssid”, SsidValue (ssid));

NetDeviceContainer apDevices = wifi.Install (wifiPhy, wifiMac, wifiApNode);

// Assign IP addresses to Wi-Fi devices

ipv4h.SetBase (“192.168.1.0”, “255.255.255.0”);

Ipv4InterfaceContainer apInterface = ipv4h.Assign (apDevices);

Ipv4InterfaceContainer staInterface = ipv4h.Assign (staDevices);

// Set up mobility

MobilityHelper mobility;

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

mobility.Install (ueNodes);

mobility.Install (enbNodes);

mobility.Install (wifiApNode);

mobility.Install (remoteHostContainer);

ueNodes.Get (0)->GetObject<MobilityModel> ()->SetPosition (Vector (0.0, 0.0, 0.0));

enbNodes.Get (0)->GetObject<MobilityModel> ()->SetPosition (Vector (100.0, 0.0, 10.0));

wifiApNode.Get (0)->GetObject<MobilityModel> ()->SetPosition (Vector (50.0, 0.0, 5.0));

// Set up applications

uint16_t port = 12345;

UdpServerHelper server (port);

ApplicationContainer serverApp = server.Install (remoteHost);

serverApp.Start (Seconds (1.0));

serverApp.Stop (Seconds (10.0));

UdpClientHelper client (remoteHostAddr, port);

client.SetAttribute (“MaxPackets”, UintegerValue (100));

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

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

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

clientApp.Start (Seconds (2.0));

clientApp.Stop (Seconds (10.0));

// Offload traffic from LTE to Wi-Fi

Simulator::Schedule (Seconds (5.0), [&]() {

Ptr<Ipv4StaticRouting> ueStaticRouting = Ipv4RoutingHelper::GetRouting<Ipv4StaticRouting> (ueNodes.Get (0)->GetObject<Ipv4> ()->GetRoutingProtocol ());

ueStaticRouting->SetDefaultRoute (apInterface.GetAddress (0), 1);

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

});

// Enable packet capturing

p2ph.EnablePcapAll (“network-offloading”);

wifiPhy.EnablePcap (“network-offloading”, apDevices.Get (0));

wifiPhy.EnablePcap (“network-offloading”, staDevices.Get (0));

// Run simulation

Simulator::Stop (Seconds (10.0));

Simulator::Run ();

Simulator::Destroy ();

return 0;

}

Explanation:

1. Create Nodes:
   • Create one UE node, one eNodeB node, one Wi-Fi AP node, and one remote host node.
2. Set Up LTE Network:
   • Use LteHelper and PointToPointEpcHelper to set up the LTE network.
   • Install LTE devices on the UE and eNodeB nodes.
   • Attach the UE to the LTE network.
3. Set Up Wi-Fi Network:
   • Use WifiHelper to set up the Wi-Fi network.
   • Install Wi-Fi devices on the UE and Wi-Fi AP nodes.
   • Assign IP addresses to the Wi-Fi devices.
4. Set Up Mobility Models:
   • Use ConstantPositionMobilityModel to set fixed positions for the UE, eNodeB, and Wi-Fi AP nodes.
5. Set Up Applications:
   • Set up a UDP server on a remote host and a UDP client on the UE to generate traffic.
6. Offload Traffic from LTE to Wi-Fi:
   • Schedule an event to modify the UE’s routing table to use the Wi-Fi network as the default route.
7. Enable Packet Capturing:
   • Enable packet capturing using the EnablePcapAll and EnablePcap methods to capture the transmitted packets.
8. Run Simulation:
   • Run the simulation and then destroy it after completion.

Step 4: Compile and Run the Script

1. Save the script as network-offloading.cc in the scratch directory of your ns-3 installation.
2. Compile the script using the following commands:

./waf configure

./waf build

./waf –run network-offloading

Step 5: Analyze the Results

After running the simulation, we will analyse the results by looking at the logs and any generated output files to verify the behaviour of the network offloading.

Finally, here we discussed about how to implement and process the Network offloading performs in ns3 simulation tool and also we see the sample references clearly in the above. We also provide all kinds of information related to Network offloading.

We are currently using the ns3tool to integrate the required code for your project, particularly to enable Network offloading. We have all the essential tools and resources to effectively finish your project. Receive a detailed explanation from our developers.