How to Start Flat Topology Projects Using NS3

To start Flat Topology using NS3 which is a network layout in which every nodes are peers and it doesn’t have hierarchical structure. This kind of topology is typically utilized within sensor networks, peer-to-peer systems, and wireless ad hoc networks. We will instruct you through the step-by-step process to get started:

Steps to Start a Flat Topology Project in NS3

Step 1: Set Up NS3

  1. Install NS3:
    • Go to NS3 webpage to download NS3.
    • We stick to the installation instructions.
  2. Verify Installation: Make sure that NS3 is properly installed with a simple example:

./waf –run scratch/my_first

Step 2: Understand Flat Topology

  • Flat Topology Characteristics:
    • These nodes interact directly or via multi-hop routes.
    • It doesn’t have central coordination or hierarchical relationships.
    • This topology typically utilised in wireless ad hoc and sensor networks.

Step 3: Plan the Topology

  1. Decide the number of nodes:
    • For instance, we define the volume of nodes that has 10 nodes.
  2. Set simulation goals:
    • We estimate the performance indicators such as throughput, delay, and packet delivery ratio in the topology.
    • In a flat topology, experiment the routing protocols such as AODV or OLSR.
  3. Layout the nodes:
    • Set the nodes arbitrarily or within a grid.

Step 4: Set Up the Flat Topology

  1. Create Nodes: We can able to make nodes within the network.

NodeContainer nodes;

uint32_t numNodes = 10;

nodes.Create(numNodes);

  1. Set Up Wireless Devices: Make use of Wi-Fi or any other wireless technology to configure wireless devices.

WifiHelper wifi;

wifi.SetStandard(WIFI_PHY_STANDARD_80211b);

YansWifiPhyHelper phy = YansWifiPhyHelper::Default();

phy.Set(“RxGain”, DoubleValue(-10)); // Example receiver gain

YansWifiChannelHelper channel = YansWifiChannelHelper::Default();

phy.SetChannel(channel.Create());

WifiMacHelper mac;

mac.SetType(“ns3::AdhocWifiMac”);

NetDeviceContainer devices = wifi.Install(phy, mac, nodes);

  1. Set Up Mobility: We need to set nodes randomly or within a grid.

MobilityHelper mobility;

mobility.SetPositionAllocator(“ns3::RandomRectanglePositionAllocator”,

“X”, StringValue(“ns3::UniformRandomVariable[Min=0.0|Max=100.0]”),

“Y”, StringValue(“ns3::UniformRandomVariable[Min=0.0|Max=100.0]”));

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

mobility.Install(nodes);

  1. Install Internet Stack: Insert the Internet stack and then set routing protocols.

InternetStackHelper stack;

stack.Install(nodes);

AodvHelper aodv; // Example routing protocol

Ipv4ListRoutingHelper list;

list.Add(aodv, 10);

stack.SetRoutingHelper(list);

Ipv4AddressHelper address;

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

Ipv4InterfaceContainer interfaces = address.Assign(devices);

Step 5: Simulate Traffic

  1. Set Up Traffic Sources: We require to install applications making traffic.
    • UDP Echo Example:

UdpEchoServerHelper echoServer(9); // Port 9

ApplicationContainer serverApp = echoServer.Install(nodes.Get(0)); // Server on Node 0

serverApp.Start(Seconds(1.0));

serverApp.Stop(Seconds(10.0));

UdpEchoClientHelper echoClient(Ipv4Address(“10.1.1.1”), 9); // Server’s IP

echoClient.SetAttribute(“MaxPackets”, UintegerValue(10));

echoClient.SetAttribute(“Interval”, TimeValue(Seconds(1.0)));

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

ApplicationContainer clientApp = echoClient.Install(nodes.Get(3)); // Client on Node 3

clientApp.Start(Seconds(2.0));

clientApp.Stop(Seconds(10.0));

  1. Use Flow Monitor: We should compute the performance parameters such as throughput, delay, and packet loss with the support of Flow Monitor.

FlowMonitorHelper flowmon;

Ptr<FlowMonitor> monitor = flowmon.InstallAll();

Step 6: Run and Analyze

  1. Run the Simulation: Now, we execute the simulation using below code.

Simulator::Run();

Simulator::Destroy();

  1. Enable Packet Capture: Allow packet to seize and we save .pcap files for traffic analysis.

phy.EnablePcapAll(“flat_topology”);

  1. Analyze Results: Examine the network performance to utilize the Flow Monitor.

monitor->SerializeToXmlFile(“flat_topology_flowmon.xml”, true, true);

Example: Minimal NS3 Script for Flat Topology

#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/flow-monitor-module.h”

using namespace ns3;

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

uint32_t numNodes = 10;

// Create nodes

NodeContainer nodes;

nodes.Create(numNodes);

// Configure Wi-Fi

WifiHelper wifi;

wifi.SetStandard(WIFI_PHY_STANDARD_80211b);

YansWifiPhyHelper phy = YansWifiPhyHelper::Default();

phy.Set(“RxGain”, DoubleValue(-10));

YansWifiChannelHelper channel = YansWifiChannelHelper::Default();

phy.SetChannel(channel.Create());

WifiMacHelper mac;

mac.SetType(“ns3::AdhocWifiMac”);

NetDeviceContainer devices = wifi.Install(phy, mac, nodes);

// Configure mobility

MobilityHelper mobility;

mobility.SetPositionAllocator(“ns3::RandomRectanglePositionAllocator”,

“X”, StringValue(“ns3::UniformRandomVariable[Min=0.0|Max=100.0]”),

“Y”, StringValue(“ns3::UniformRandomVariable[Min=0.0|Max=100.0]”));

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

mobility.Install(nodes);

// Install Internet stack and routing

InternetStackHelper stack;

stack.Install(nodes);

AodvHelper aodv;

Ipv4ListRoutingHelper list;

list.Add(aodv, 10);

stack.SetRoutingHelper(list);

Ipv4AddressHelper address;

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

Ipv4InterfaceContainer interfaces = address.Assign(devices);

// Set up UDP echo server

UdpEchoServerHelper echoServer(9);

ApplicationContainer serverApp = echoServer.Install(nodes.Get(0));

serverApp.Start(Seconds(1.0));

serverApp.Stop(Seconds(10.0));

// Set up UDP echo client

UdpEchoClientHelper echoClient(interfaces.GetAddress(0), 9);

echoClient.SetAttribute(“MaxPackets”, UintegerValue(10));

echoClient.SetAttribute(“Interval”, TimeValue(Seconds(1.0)));

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

ApplicationContainer clientApp = echoClient.Install(nodes.Get(3));

clientApp.Start(Seconds(2.0));

clientApp.Stop(Seconds(10.0));

// Set up Flow Monitor

FlowMonitorHelper flowmon;

Ptr<FlowMonitor> monitor = flowmon.InstallAll();

// Enable packet capture

phy.EnablePcapAll(“flat_topology”);

// Run simulation

Simulator::Run();

Simulator::Destroy();

// Save Flow Monitor results

monitor->SerializeToXmlFile(“flat_topology_flowmon.xml”, true, true);

return 0;

}

Step 7: Enhance the Simulation

  • Dynamic Mobility:
    • Mimic node movement get through models such as RandomWalk2D.
  • Test Different Protocols:
    • We need to equate AODV, DSDV, and OLSR for routing performance.
  • Analyze Traffic Patterns:
    • Examine the traffic patterns like TCP, FTP, or HTTP traffic for realistic scenarios.
  • Visualize:
    • Envision the flat topology and data flow exploiting NetAnim.

We have performed the project approach step by step along with sample snippets for Flat Topology projects, which were simulated and examined within NS3 tool. We can look into further detail upon request.

To start of your Flat Topology Projects with NS3, we will carry out simulations tailored to your specific needs. Our team will provide complete support throughout the entire process to guarantee the successful completion of your project.