How to Begin Implement a GPSR protocol in NS3

To create a Greedy Perimeter Stateless Routing (GPSR) protocol in ns3 tool has making the custom routing protocol tailored for geographic routing. GPSR used the place for node and create forwarding decisions, goal for transmitting the packets nearby to destination using greedy or perimeter forwarding

Although ns-3 doesn’t natively maintenance for GPSR, we can apply through encompass the routing framework or using existing geographic values. Below is a structured guide for implementing GPSR in ns-3.

Steps to Begin Implement a GPSR protocol in NS3

1. Understand GPSR Protocol

• Key Features:
  • Greedy Forwarding: Forward packets to nearby neighbor the destination.
  • Perimeter Forwarding: Used after greedy promoting the fails for instance local maxima.
  • Stateless: Nodes has handled the neighbor positions, and decrease the overhead.
• Requirements:
  • Every node must know its geographic position such as requires a mobility model.
  • Nodes are modifying the placed information by neighbors.

2. Set Up ns-3 Environment

1. Install ns-3:

git clone https://gitlab.com/nsnam/ns-3-dev.git

cd ns-3-dev

./build.py

1. Verify the installation:

./ns3 run hello-simulator

3. Plan the Network Topology

• Components:
  • Mobile nodes are prepared by geographic routing abilities.
  • Traffic source and destination nodes.
• Topology:
  • Use arbitrary employment or mobility patterns for nodes.

4. Create the GPSR Protocol
5. Define the Protocol Class

1. Create a new class inheriting from Ipv4RoutingProtocol:

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

#include “ns3/mobility-module.h”

class GpsrRouting : public ns3::Ipv4RoutingProtocol {

public:

GpsrRouting();

virtual ~GpsrRouting();

Ptr<Ipv4Route> RouteOutput(Ptr<Packet> packet, const Ipv4Header &header,

Ptr<NetDevice> oif, Socket::SocketErrno &sockerr) override;

bool RouteInput(Ptr<const Packet> packet, const Ipv4Header &header,

Ptr<const NetDevice> idev, UnicastForwardCallback ucb,

MulticastForwardCallback mcb, LocalDeliverCallback lcb,

ErrorCallback ecb) override;

void AddPositionInfo();

void PerformGreedyForwarding();

void PerformPerimeterForwarding();

private:

ns3::Ipv4Address GetClosestNeighbor(ns3::Vector destPosition);

};

1. Greedy Forwarding:
   • Forward the packet for nearby neighbor to the destination.
   • Use Vector functions to measure the distances.
2. Perimeter Forwarding:
   • Use planar graph traversal procedures like as the right-hand rule.

1. Integrate GPSR Logic

1. Neighbor Table Maintenance:
   • Nodes have periodically propagated their position using control packets.
   • Use Socket APIs to direct and receive the location for bring up-to-date.
2. Routing Decisions:
   • Use the node’s for MobilityModel to get placed.
   • Find the near neighbor using measure a distance.
3. Error Handling:
   • Apply the fallback to perimeter advancing after greedy forwarding fails.

1. Create a Helper Class

1. Explain a assistant for installing the GPSR protocol:

class GpsrHelper : public ns3::Ipv4RoutingHelper {

public:

GpsrHelper() {}

Ptr<Ipv4RoutingProtocol> Create(Ptr<Node> node) const override {

return CreateObject<GpsrRouting>();

}

};

1. Install the helper in your simulation script:

GpsrHelper gpsrHelper;

ns3::InternetStackHelper stack;

stack.SetRoutingHelper(gpsrHelper);

stack.Install(nodes);

5. Set Up the Simulation
6. Define Nodes

ns3::NodeContainer nodes;

nodes.Create(10);  // Create 10 mobile nodes

1. Set Up Mobility

1. Random Mobility Model:

ns3::MobilityHelper mobility;

mobility.SetMobilityModel(“ns3::RandomWaypointMobilityModel”,

“Speed”, ns3::StringValue(“ns3::UniformRandomVariable[Min=5.0|Max=20.0]”),

“Pause”, ns3::StringValue(“ns3::ConstantRandomVariable[Constant=2.0]”),

“PositionAllocator”, ns3::StringValue(“ns3::RandomRectanglePositionAllocator”));

mobility.Install(nodes);

1. Static Placement (Optional):

ns3::MobilityHelper mobility;

mobility.SetPositionAllocator(“ns3::GridPositionAllocator”,

“MinX”, ns3::DoubleValue(0.0),

“MinY”, ns3::DoubleValue(0.0),

“DeltaX”, ns3::DoubleValue(50.0),

“DeltaY”, ns3::DoubleValue(50.0),

“GridWidth”, ns3::UintegerValue(5),

“LayoutType”, ns3::StringValue(“RowFirst”));

mobility.Install(nodes);

1. Set Up Wi-Fi Communication

ns3::WifiHelper wifi;

wifi.SetStandard(ns3::WIFI_PHY_STANDARD_80211p);  // 802.11p for VANETs

ns3::WifiMacHelper mac;

mac.SetType(“ns3::AdhocWifiMac”);

ns3::WifiPhyHelper phy = ns3::WifiPhyHelper::Default();

phy.SetChannel(ns3::YansWifiChannelHelper::Default().Create());

ns3::NetDeviceContainer devices = wifi.Install(phy, mac, nodes);

1. Assign IP Addresses

ns3::Ipv4AddressHelper address;

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

ns3::Ipv4InterfaceContainer interfaces = address.Assign(devices);

6. Generate Traffic

UDP Traffic

// UDP Echo server on Node 9

ns3::UdpEchoServerHelper echoServer(9);

ns3::ApplicationContainer serverApp = echoServer.Install(nodes.Get(9));

serverApp.Start(ns3::Seconds(1.0));

serverApp.Stop(ns3::Seconds(20.0));

// UDP Echo client on Node 0

ns3::UdpEchoClientHelper echoClient(address.Assign(devices).GetAddress(9), 9);

echoClient.SetAttribute(“MaxPackets”, ns3::UintegerValue(10));

echoClient.SetAttribute(“Interval”, ns3::TimeValue(ns3::Seconds(1.0)));

echoClient.SetAttribute(“PacketSize”, ns3::UintegerValue(512));

ns3::ApplicationContainer clientApp = echoClient.Install(nodes.Get(0));

clientApp.Start(ns3::Seconds(2.0));

clientApp.Stop(ns3::Seconds(20.0));

7. Run the Simulation

ns3::Simulator::Run();

ns3::Simulator::Destroy();

8. Analyze Results

Metrics:

• Packet Delivery Ratio (PDR):
  • Estimate the ratio of packets are successfully delivered.
• Latency:
  • Calculate the average delay for packet delivery.
• Control Overhead:
  • Amount the control messages are modified.

Tracing and Visualization:

• Ensure the files .pcap tracing for packet inspection:

ns3::AsciiTraceHelper ascii;

phy.EnableAsciiAll(ascii.CreateFileStream(“gpsr.tr”));

phy.EnablePcapAll(“gpsr”);

• Tool like NetAnim for used the envision:

./waf –run “gpsr-simulation –vis”

9. Iterate and Enhance

• Advanced Scenarios:
  • Investigation by higher mobility or node density.
  • It replicates the connection or node failures.
• Optimization:
  • Enhance the neighbor discovery and perimeter routing devices.
• Protocol Comparison:
  • Associate the GPSR by AODV, DSR, and other protocols.

By means of the ns3 analysis tool had been illustrated the core methods for Greedy Perimeter Stateless Routing project that were simulated, envisioned and enhanced the outcomes. Advance details will be provided regarding this Greedy Perimeter Stateless Routing.