How to Begin Implement Star Protocol in NS3

To Implement the Source Tree Adaptive Routing (STAR) protocol in NS3 environment has includes the model its unique characters and behavior for effective routing in wireless or mobile ad-hoc networks. STAR is proactive, with source trees has handle the routing data and minimize control overhead. Below is a detailed guide to start implementing STAR in NS-3:

Steps to Begin Implement Star Protocol in NS3

Step 1: Understand STAR Protocol

• Key Features:
  • Proactive protocol which retains the source trees for every node.
  • Reduces the control overhead using LORA (Least Overhead Routing Approach).
  • After required the tree has brought up-to-date source such as adaptive behavior.
• Components:
  • Source Tree: It continues the routes for all reachable nodes.
  • Update Messages: Used to broadcast routing information like as Triggered and Periodic.
  • Adaptive Behavior: bring up-to-date are decreases through transfer after variations are occur.

Step 2: Familiarize Yourself with NS-3

• Study the NS-3’s environment using the routing pattern through examine an existing protocols:
  • AODV: src/aodv/
  • OLSR: src/olsr/
• Appreciate the Ipv4RoutingProtocol class that serves as the base for applying routing protocols.

Step 3: Set Up NS-3 for Development

1. Create a New Protocol Directory:
   • Make a directory below src/ for the protocol for instance src/star/.
2. Add Required Files:
   • star-routing-protocol.h: Describe the protocol’s feature and API.
   • star-routing-protocol.cc: Apply the logic for protocol.
   • star-helper.h and star-helper.cc: Deliver the helper class for replication.
3. Update Build System:
   • Alter to contain the new protocol wscript.

Step 4: Design the STAR Protocol

1. Define Protocol Class

Encompass the Ipv4RoutingProtocol class to apply the STAR.

#include “ns3/ipv4-routing-protocol.h”

#include “ns3/ipv4-address.h”

#include “ns3/timer.h”

#include “ns3/socket.h”

class StarRoutingProtocol : public ns3::Ipv4RoutingProtocol {

public:

static ns3::TypeId GetTypeId (void);

StarRoutingProtocol ();

virtual ~StarRoutingProtocol ();

// Override Ipv4RoutingProtocol methods

virtual ns3::Ptr<ns3::Ipv4Route> RouteOutput (

ns3::Ptr<const ns3::Packet> packet,

const ns3::Ipv4Header &header,

ns3::Ptr<ns3::NetDevice> oif,

ns3::Socket::SocketErrno &sockerr);

virtual bool RouteInput (

ns3::Ptr<const ns3::Packet> packet,

const ns3::Ipv4Header &header,

ns3::Ptr<const ns3::NetDevice> idev,

ns3::UnicastForwardCallback ucb,

ns3::MulticastForwardCallback mcb,

ns3::LocalDeliverCallback lcb,

ns3::ErrorCallback ecb);

// STAR-specific methods

void UpdateSourceTree ();  // Updates the source tree

void SendUpdateMessage (); // Sends routing updates

void ProcessUpdateMessage (ns3::Ptr<const ns3::Packet> packet); // Processes received updates

private:

ns3::Ipv4Address m_selfAddress; // Node’s own address

std::map<ns3::Ipv4Address, std::vector<ns3::Ipv4Address>> m_sourceTree; // Source tree

ns3::Timer m_updateTimer; // Timer for periodic updates

};

2. Implement Key Components

• Source Tree:
  • Keep the table plotting endpoints for paths.
  • Uses the source tree for adjacency lists or equal data structures.
• Update Messages:
  • Express the format and feature of bring up-to-date communication.
  • Apply the procedures for serialize and deserialize these communications.

Sample of a custom header for STAR:

#include “ns3/header.h”

class StarUpdateHeader : public ns3::Header {

public:

static ns3::TypeId GetTypeId (void);

virtual TypeId GetInstanceTypeId () const;

void AddEntry (ns3::Ipv4Address dest, ns3::Ipv4Address nextHop);

virtual void Serialize (ns3::Buffer::Iterator start) const;

virtual uint32_t Deserialize (ns3::Buffer::Iterator start);

virtual void Print (std::ostream &os) const;

private:

std::vector<std::pair<ns3::Ipv4Address, ns3::Ipv4Address>> m_entries; // Destination and next-hop pairs

};

• Routing Logic:
  • Apply the adaptive bring up-to-date generation according to the topology variations.
  • Use the periodic and bring up-to-date the event-driven.

Example:

void StarRoutingProtocol::UpdateSourceTree () {

// Logic to update the source tree

}

void StarRoutingProtocol::SendUpdateMessage () {

// Construct and broadcast an update message

ns3::Ptr<ns3::Packet> packet = ns3::Create<ns3::Packet> ();

StarUpdateHeader header;

// Add entries to the header

packet->AddHeader(header);

BroadcastPacket(packet);

}

void StarRoutingProtocol::ProcessUpdateMessage (ns3::Ptr<const ns3::Packet> packet) {

// Extract and process the update message

StarUpdateHeader header;

packet->PeekHeader(header);

// Update the source tree based on received entries

}

3. Timers

Use devices for periodic challenges like sending bring up-to-date.

Example:

m_updateTimer.SetFunction(&StarRoutingProtocol::SendUpdateMessage, this);

m_updateTimer.Schedule(ns3::Seconds(5)); // Schedule periodic updates every 5 seconds

Step 5: Write a Helper Class

Make a helper class for enable the installation for STAR replication scripts.

#include “star-routing-protocol.h”

class StarHelper {

public:

void Install (ns3::NodeContainer nodes) {

for (auto it = nodes.Begin(); it != nodes.End(); ++it) {

ns3::Ptr<StarRoutingProtocol> protocol = ns3::CreateObject<StarRoutingProtocol>();

(*it)->AggregateObject(protocol);

}

}

};

Step 6: Write Simulation Script

Make a script for validate the STAR functionality in a network.

Example:

#include “ns3/core-module.h”

#include “ns3/network-module.h”

#include “ns3/internet-module.h”

#include “star-helper.h”

int main () {

ns3::NodeContainer nodes;

nodes.Create(5);

ns3::InternetStackHelper stack;

stack.Install(nodes);

StarHelper starHelper;

starHelper.Install(nodes);

// Create and configure traffic sources, sinks, and network topology

ns3::Simulator::Run();

ns3::Simulator::Destroy();

return 0;

}

Step 7: Compile and Test

1. Compile:

./waf configure

./waf build

1. Run Simulation:

./waf –run your-script

From the explanation, we understood the clear explanation about how to simulate the scenarios, configuration setup and how to analyse the outcomes for the STAR protocol that were executed using ns3 tool. Please refer to the supplementary manual for any project-related inquiries.