How to Begin Implement Cellular Topology in NS3

To implement a cellular topology using NS3 which needs to replicate a network in which base stations (eNodeBs) function at numerous mobile devices (UEs) in its coverage area. It is generally utilized within LTE, 5G, or other mobile interaction simulations.

Below is a common procedure on how to execute a Cellular Topology in NS3:

Steps to Begin Implement Cellular Topology in NS3

1. Understand the Cellular Topology

• Base Stations (eNodeBs): It performs like central point for interaction, and handling the associated devices.
• User Equipment (UEs): Mobile devices, which associate to the base station.
• Backhaul Network: Base stations could link to a central gateway for Internet access.

2. Set Up NS3

1. Install NS3 with LTE Module:
   • Make sure that we have installed NS3 and LTE module.
   • Confirm the set up by executing:

./waf –run lte-simple

1. Install Wireshark:
   • For packet-level analysis, we can examine .pcap files.

3. Design the Cellular Topology

Create a cellular topology including:

• 1 or more base stations (eNodeBs).
• Numerous UEs are linked to every single eNodeB.
• Only one PGW (Packet Gateway) to offer Internet access.

Define the Network Components

Make the eNodeBs, UEs, and link them:

#include “ns3/core-module.h”

#include “ns3/network-module.h”

#include “ns3/lte-module.h”

#include “ns3/internet-module.h”

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

#include “ns3/applications-module.h”

using namespace ns3;

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

// Create LTE helper

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

// Create Internet helper

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

lteHelper->SetEpcHelper(epcHelper);

// Create a remote host for Internet access

NodeContainer remoteHostContainer;

remoteHostContainer.Create(1);

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

InternetStackHelper internet;

internet.Install(remoteHostContainer);

// Create the PGW and connect to remote host

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

PointToPointHelper p2pInternet;

p2pInternet.SetDeviceAttribute(“DataRate”, StringValue(“100Gbps”));

p2pInternet.SetChannelAttribute(“Delay”, StringValue(“2ms”));

NetDeviceContainer internetDevices = p2pInternet.Install(pgw, remoteHost);

Ipv4AddressHelper ipv4h;

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

ipv4h.Assign(internetDevices);

// Install applications on the remote host

uint16_t port = 80;

Address sinkAddress(InetSocketAddress(Ipv4Address::GetAny(), port));

PacketSinkHelper packetSinkHelper(“ns3::UdpSocketFactory”, sinkAddress);

ApplicationContainer sinkApps = packetSinkHelper.Install(remoteHost);

sinkApps.Start(Seconds(1.0));

sinkApps.Stop(Seconds(10.0));

// Create eNodeBs

NodeContainer enbNodes;

enbNodes.Create(2); // Two base stations

// Create UEs

NodeContainer ueNodes;

ueNodes.Create(4); // Four UEs

// Install LTE Devices

NetDeviceContainer enbLteDevs = lteHelper->InstallEnbDevice(enbNodes);

NetDeviceContainer ueLteDevs = lteHelper->InstallUeDevice(ueNodes);

// Install Internet stack on UEs

internet.Install(ueNodes);

// Assign IPs to UEs

Ipv4InterfaceContainer 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()));

}

// Set default gateway for UEs

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

Ptr<Ipv4StaticRouting> ueStaticRouting = Ipv4RoutingHelper::GetRouting<Ipv4StaticRouting>(

ueNodes.Get(i)->GetObject<Ipv4>()->GetRoutingProtocol());

ueStaticRouting->SetDefaultRoute(epcHelper->GetUeDefaultGatewayAddress(), 1);

}

// Install applications on UEs

UdpClientHelper clientHelper(Ipv4Address(“1.0.0.1”), port); // Remote host IP

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

clientHelper.SetAttribute(“Interval”, TimeValue(MilliSeconds(10)));

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

ApplicationContainer clientApps = clientHelper.Install(ueNodes);

clientApps.Start(Seconds(2.0));

clientApps.Stop(Seconds(10.0));

// Enable tracing

lteHelper->EnableTraces();

p2pInternet.EnablePcapAll(“cellular-topology”);

// Run simulation

Simulator::Run();

Simulator::Destroy();

return 0;

}

4. Explanation

• eNodeBs and UEs: In the topology, every single UE is linked to an eNodeB.
• Internet Access: The PGW is associated to the distant host with a P2P link.
• Applications: UEs perform like clients to transmit the information to a remote host functioning as the server.

5. Simulation Output

• The simulation script launches associations among UEs and the Internet.
• Packet Traces: .pcap files are created for examining the traffic flow.
• LTE Statistics: LTE-specific parameters such as SINR, throughput, and delay can be examined.

6. Extend the Simulation

• Add More Nodes: Maximize the volume of UEs and eNodeBs.
• Vary Mobility: Replicate the UEs moving among base stations using NS3 Mobility pattern.
• Add Traffic Types: Mimic various application types like video streaming, voice.

7. Verify Results

• Examine the .pcap files to leverage the tools like Wireshark.
• Confirm connectivity of UEs into the Internet.
• Monitor the performance parameters such as throughput, latency, and packet loss.

This guide focuses on how to implement the Cellular Topology, how to expand the simulation and analyse the outcomes through the above execution method using NS3 environment. Additional insights tailored to your needs can be delivered.