How to Implement a Wireless Routing Protocol in NS3

To begin executing a wireless routing protocol using ns3 which needs to model or set up a routing protocol that particularly customized for wireless networks. NS3 has numerous inherent wireless routing protocols like AODV, DSDV, OLSR, and DSR that can be utilized like a basis for the execution. On the other hand, we will need to make a custom wireless routing protocol.

Below is a structured guide on how to implement a wireless routing protocol using NS3:

Steps to Begin Implement a Wireless Routing Protocol in NS3

1. Understand Wireless Routing Protocols

• Key Characteristics:
  • It is intended for dynamic and frequent mobile wireless networks.
  • Address efficient route discovery and maintenance by reason of changing topologies.
  • Probably we can utilise proactive routing protocol such as OLSR, reactive like AODV, or hybrid.
• Examples of Wireless Routing Protocols:
  • Proactive: DSDV, OLSR which supports to continuously sustain routes.
  • Reactive: AODV, DSR that determine the paths on-demand.
  • Hybrid: ZRP (Zone Routing Protocol).

2. Set Up ns3 Environment

1. Install ns3:

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 Wireless Network Topology

• Components:
  • In wireless network, mobile or static nodes are denoting the devices.
  • A traffic generator to replicate the data transmission among nodes.
• Topology:
  • Make use of mobility patterns for dynamic node placement.
  • Describe a Wi-Fi or ad hoc network for interaction.

4. Set Up the Wireless Network
5. Include Necessary Headers

#include “ns3/core-module.h”

#include “ns3/network-module.h”

#include “ns3/internet-module.h”

#include “ns3/mobility-module.h”

#include “ns3/wifi-module.h”

#include “ns3/aodv-helper.h”    // Replace with another protocol helper if needed

#include “ns3/applications-module.h”

1. Create Nodes

ns3::NodeContainer nodes;

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

1. Set Up Mobility

ns3::MobilityHelper mobility;

// Random waypoint mobility model

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.SetPositionAllocator(“ns3::RandomRectanglePositionAllocator”,

“X”, ns3::StringValue(“ns3::UniformRandomVariable[Min=0.0|Max=500.0]”),

“Y”, ns3::StringValue(“ns3::UniformRandomVariable[Min=0.0|Max=500.0]”));

mobility.Install(nodes);

1. Set Up Wi-Fi Communication

ns3::WifiHelper wifi;

wifi.SetStandard(ns3::WIFI_PHY_STANDARD_80211g);

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);

5. Install the Wireless Routing Protocol
6. Using a Built-in Protocol

1. AODV Example:

ns3::AodvHelper aodv;

ns3::InternetStackHelper stack;

stack.SetRoutingHelper(aodv);  // Use AODV as the routing protocol

stack.Install(nodes);

1. Other Protocols: Substitute AodvHelper including:
   • OlsrHelper for OLSR.
   • DsdvHelper for DSDV.
   • DsrHelper for DSR.

1. Custom Wireless Routing Protocol

If improving a custom protocol, we can:

1. Create a New Routing Class:
   • Originate from Ipv4RoutingProtocol.
   • Execute the mechanisms such as RouteOutput and RouteInput.

Example Skeleton:

class CustomRoutingProtocol : public ns3::Ipv4RoutingProtocol {

public:

CustomRoutingProtocol() {}

virtual ~CustomRoutingProtocol() {}

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

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

// Add custom routing logic here

return nullptr;

}

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

Ptr<const NetDevice> idev, UnicastForwardCallback ucb,

MulticastForwardCallback mcb, LocalDeliverCallback lcb,

ErrorCallback ecb) override {

// Add logic to handle incoming packets

return false;

}

};

1. Integrate the Protocol:
   • Make a helper for custom protocol.
   • We need to install the protocol to utilize InternetStackHelper.

6. Assign IP Addresses

ns3::Ipv4AddressHelper address;

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

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

7. Generate Traffic

UDP Traffic

// UDP Echo server on node 0

ns3::UdpEchoServerHelper echoServer(9);

ns3::ApplicationContainer serverApp = echoServer.Install(nodes.Get(0));

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

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

// UDP Echo client on node 9

ns3::UdpEchoClientHelper echoClient(interfaces.GetAddress(0), 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(9));

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

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

8. Run the Simulation

ns3::Simulator::Run();

ns3::Simulator::Destroy();

9. Analyze Results

Metrics:

• Packet Delivery Ratio (PDR):
  • Estimate the percentage of packets that are effectively distributed to entire transmitted packets.
• End-to-End Delay:
  • Measure the average delay to attain its end for packets.
• Routing Overhead:
  • During the simulation, determine the control messages which are transmitted.

Tracing and Visualization:

• Allow .pcap tracing for packet analysis:

ns3::AsciiTraceHelper ascii;

phy.EnableAsciiAll(ascii.CreateFileStream(“wireless-routing.tr”));

phy.EnablePcapAll(“wireless-routing”);

• Make use of NetAnim for visualization:

./waf –run “wireless-routing-simulation –vis”

10. Iterate and Enhance

• Advanced Scenarios:
  • Replicate link or node failures for assessing the robustness of protocol.
  • Experiment with high mobility to examine flexibility of protocol.
• Traffic Patterns:
  • Launch TCP-based traffic or simultaneous data streams.
• Protocol Comparison:
  • Experiment the performance of numerous routing protocols like AODV, OLSR in same network conditions.

11. Custom Protocol Extensions

1. Fine-tune an existing routing protocol such as AODV within src/aodv.
2. Prolong the mechanisms with new aspects.
3. Recompile ns3 by using:

./waf

With NS3 tool, we executed a detailed implementation approach for executing and examining the Wireless Routing Protocol and we are positioned to expand on the findings as more information becomes available.