How to Begin Implement Cluster Topology in NS3

To implement Cluster Topology using NS3 that needs to gather nodes into clusters including every single cluster encompassing a cluster head, which enables interaction in the cluster and using other clusters. This topology is generally leveraged within sensor networks, MANETs, and hierarchical network designs. Here’s a guide to get started:

Steps to Implement Cluster Topology in NS3

1. Understand the Cluster Topology

• Nodes are gathered into clusters including each cluster to have:
  • Cluster Head (CH): Central node responsible to handle the cluster interaction.
  • Cluster Members (CM): Nodes in the cluster, which associates through the cluster head.
• Communication happens:
  • Among cluster heads (inter-cluster).
  • Within a cluster (intra-cluster).

2. Plan the Topology

• Specify the volume of clusters and the number of nodes for each cluster.
• Observe how the cluster heads are associated.
• Decide on the type of interaction like UDP, TCP.

3. Setup NS3 Environment

• We should install and download the NS3 simulator. If is not previously installed then we need to follow the NS3 Installation instruction.
• Make use of WifiHelper for wireless clusters or utilise PointToPointHelper for wired configurations.

4. Implement the Cluster Topology

• Gather nodes into clusters.
• Allocate one node within each cluster in the same way as cluster head.
• Associate cluster members to its corresponding cluster head.
• Connect cluster heads for inter-cluster interaction.

5. Simulate Traffic

• Replicate the intra-cluster interaction in which members communicate via cluster head.
• Mimic inter-cluster interaction among the nodes within diverse clusters.

Example Script: Cluster Topology

Here’s a comprehensive sample NS3 script for executing a basic cluster topology including three clusters.

#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”

using namespace ns3;

NS_LOG_COMPONENT_DEFINE(“ClusterTopology”);

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

{

uint32_t nClusters = 3;      // Number of clusters

uint32_t nodesPerCluster = 4; // Number of nodes per cluster

double clusterDistance = 100.0; // Distance between cluster heads

double simTime = 10.0;       // Simulation time in seconds

CommandLine cmd;

cmd.AddValue(“nClusters”, “Number of clusters”, nClusters);

cmd.AddValue(“nodesPerCluster”, “Number of nodes per cluster”, nodesPerCluster);

cmd.AddValue(“clusterDistance”, “Distance between cluster heads”, clusterDistance);

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

cmd.Parse(argc, argv);

uint32_t totalNodes = nClusters * nodesPerCluster;

// Create nodes

NodeContainer nodes;

nodes.Create(totalNodes);

NodeContainer clusterHeads;

clusterHeads.Create(nClusters);

// Configure Wi-Fi

WifiHelper wifi;

wifi.SetStandard(WIFI_STANDARD_80211b);

YansWifiPhyHelper phy = YansWifiPhyHelper::Default();

YansWifiChannelHelper channel = YansWifiChannelHelper::Default();

phy.SetChannel(channel.Create());

WifiMacHelper mac;

Ssid ssid = Ssid(“ns3-cluster-network”);

mac.SetType(“ns3::AdhocWifiMac”);

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

NetDeviceContainer chDevices = wifi.Install(phy, mac, clusterHeads);

// Set node positions

MobilityHelper mobility;

Ptr<ListPositionAllocator> positionAlloc = CreateObject<ListPositionAllocator>();

// Position cluster heads

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

{

positionAlloc->Add(Vector(i * clusterDistance, 0, 0));

}

// Position cluster members around their cluster head

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

{

double baseX = i * clusterDistance;

for (uint32_t j = 0; j < nodesPerCluster; ++j)

{

double offset = 20.0 * (j + 1);

positionAlloc->Add(Vector(baseX + offset, offset, 0));

}

}

mobility.SetPositionAllocator(positionAlloc);

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

mobility.Install(nodes);

mobility.Install(clusterHeads);

// Install Internet stack

InternetStackHelper stack;

stack.Install(nodes);

stack.Install(clusterHeads);

// Assign IP addresses

Ipv4AddressHelper address;

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

address.Assign(devices);

address.Assign(chDevices);

// Configure UDP Echo Server on cluster heads

uint16_t port = 9; // Echo port

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

{

UdpEchoServerHelper echoServer(port);

ApplicationContainer serverApp = echoServer.Install(clusterHeads.Get(i));

serverApp.Start(Seconds(1.0));

serverApp.Stop(Seconds(simTime));

}

// Configure UDP Echo Clients on cluster members

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

{

uint32_t clusterIndex = i / nodesPerCluster;

UdpEchoClientHelper echoClient(Ipv4Address(“10.1.1.1”), port);

echoClient.SetAttribute(“MaxPackets”, UintegerValue(5));

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

echoClient.SetAttribute(“PacketSize”, UintegerValue(512));

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

clientApp.Start(Seconds(2.0));

clientApp.Stop(Seconds(simTime));

}

// Enable tracing

AsciiTraceHelper ascii;

phy.EnableAsciiAll(ascii.CreateFileStream(“cluster-topology.tr”));

phy.EnablePcapAll(“cluster-topology”);

// Run simulation

Simulator::Stop(Seconds(simTime));

Simulator::Run();

Simulator::Destroy();

return 0;

}

Explanation of the Script

1. Topology:
   • This topology contains three clusters; each cluster has one cluster head and four cluster members.
   • Cluster heads are located within a line using a distance of clusterDistance.
2. Wi-Fi Configuration:
   • Every single cluster functions like an ad-hoc Wi-Fi network.
3. Applications:
   • Each cluster head executes a UDP Echo Server.
   • Cluster members perform like UDP Echo Clients for transmitting the traffic to its corresponding cluster heads.
4. Tracing:
   • ASCII and PCAP tracing are used for seizing network activity.

Steps to Run and Analyze

1. Compile and Run the Script:

./waf –run “cluster-topology”

1. Analyze Logs:
   • Confirm records for traffic flows in and among the clusters.
2. Packet Analysis:
   • Examine the PCAP files using Wireshark for in-depth packet-level inspection.

Enhancements

1. Inter-Cluster Communication:
   • Integrate interaction among the cluster heads.
2. Routing Protocols:
   • Execute routing protocols such as AODV or OLSR in and among the clusters for dynamic routing.
3. Performance Metrics:
   • Assess the performance parameters such as latency, throughput, and packet delivery ratio for the topology.
4. Dynamic Traffic:
   • Replicate traffic among random pairs of nodes in and through clusters.
5. Mobility:
   • Launch mobility to leverage RandomWaypointMobilityModel for cluster members.

At the end, Cluster Topology’s implementation strategy has been laid out systematically using NS3 environment that encompasses several steps, core concepts and comprehensive sample coding. We are prepared to offer additional insights if asked.