To implement the range-free localization in ns3, we need to encompass a wireless sensor network (WSN) to calculate the nodes by their positions based on the connectivity data with their neighbours that relatively using the distance measurements. This method usually used in the scenarios where correct distance measurements are challenging or expensive to acquire.
Here are the step-by-step procedures to implement the Range-Free Localization in ns3.
Step-by-Step Implementation:
Step 1: Setup ns3 Environment
Make sure ns3 is installed in the system and appropriately configured.
git clone https://gitlab.com/nsnam/ns-3-dev.git
cd ns-3-dev
./waf configure
./waf build
Step 2: Create the Range-Free Localization Simulation Script
We will create a script that sets up a WSN with nodes estimating their positions based on the Average Hop Count (AHC) algorithm, a common range-free localization technique.
#include “ns3/core-module.h”
#include “ns3/network-module.h”
#include “ns3/internet-module.h”
#include “ns3/point-to-point-module.h”
#include “ns3/mobility-module.h”
#include “ns3/applications-module.h”
#include “ns3/wifi-module.h”
using namespace ns3;
NS_LOG_COMPONENT_DEFINE(“RangeFreeLocalizationExample”);
class LocalizationNode
{
public:
LocalizationNode(Ptr<Node> node)
: m_node(node), m_estimatedPosition(Vector(0.0, 0.0, 0.0)), m_isAnchor(false) {}
void SetAnchorPosition(Vector position)
{
m_position = position;
m_isAnchor = true;
}
void EstimatePosition(const std::vector<Ptr<LocalizationNode>> &anchors)
{
if (m_isAnchor)
{
m_estimatedPosition = m_position;
return;
}
Vector sumPosition(0.0, 0.0, 0.0);
uint32_t count = 0;
for (auto anchor : anchors)
{
if (anchor->IsAnchor())
{
sumPosition += anchor->GetPosition();
count++;
}
}
if (count > 0)
{
m_estimatedPosition = sumPosition / count;
}
}
Vector GetPosition() const { return m_position; }
Vector GetEstimatedPosition() const { return m_estimatedPosition; }
bool IsAnchor() const { return m_isAnchor; }
private:
Ptr<Node> m_node;
Vector m_position;
Vector m_estimatedPosition;
bool m_isAnchor;
};
void LogPosition(Ptr<LocalizationNode> locNode)
{
if (locNode->IsAnchor())
{
NS_LOG_UNCOND(“Anchor node at position: ” << locNode->GetPosition());
}
else
{
NS_LOG_UNCOND(“Node estimated position: ” << locNode->GetEstimatedPosition());
}
}
int main(int argc, char *argv[])
{
CommandLine cmd;
cmd.Parse(argc, argv);
// Create nodes
NodeContainer nodes;
nodes.Create(10); // Ten nodes in total
// Create localization nodes
std::vector<Ptr<LocalizationNode>> locNodes;
for (uint32_t i = 0; i < nodes.GetN(); ++i)
{
locNodes.push_back(CreateObject<LocalizationNode>(nodes.Get(i)));
}
// Set anchors
locNodes[0]->SetAnchorPosition(Vector(0.0, 0.0, 0.0));
locNodes[1]->SetAnchorPosition(Vector(100.0, 0.0, 0.0));
locNodes[2]->SetAnchorPosition(Vector(50.0, 100.0, 0.0));
// Set up mobility model
MobilityHelper mobility;
mobility.SetPositionAllocator(“ns3::GridPositionAllocator”,
“MinX”, DoubleValue(0.0),
“MinY”, DoubleValue(0.0),
“DeltaX”, DoubleValue(20.0),
“DeltaY”, DoubleValue(20.0),
“GridWidth”, UintegerValue(5),
“LayoutType”, StringValue(“RowFirst”));
mobility.SetMobilityModel(“ns3::ConstantPositionMobilityModel”);
mobility.Install(nodes);
// Set up WiFi
WifiHelper wifi;
wifi.SetRemoteStationManager(“ns3::AarfWifiManager”);
WifiMacHelper mac;
Ssid ssid = Ssid(“ns-3-ssid”);
mac.SetType(“ns3::AdhocWifiMac”,
“Ssid”, SsidValue(ssid));
YansWifiPhyHelper phy = YansWifiPhyHelper::Default();
YansWifiChannelHelper channel = YansWifiChannelHelper::Default();
phy.SetChannel(channel.Create());
NetDeviceContainer devices = wifi.Install(phy, mac, nodes);
// Install the internet stack
InternetStackHelper stack;
stack.Install(nodes);
// Assign IP addresses
Ipv4AddressHelper address;
address.SetBase(“10.1.1.0”, “255.255.255.0”);
Ipv4InterfaceContainer interfaces = address.Assign(devices);
// Estimate positions
for (auto node : locNodes)
{
node->EstimatePosition(locNodes);
}
// Log positions
for (auto node : locNodes)
{
Simulator::Schedule(Seconds(1.0), &LogPosition, node);
}
// Run the simulation
Simulator::Stop(Seconds(2.0));
Simulator::Run();
Simulator::Destroy();
return 0;
}
Step 3: Compile and Run the Simulation
- Compile the Simulation:
./waf configure –enable-examples
./waf build
Run the Simulation:
./waf –run scratch/range-free-localization-example
Step 4: Analyse Results
The simulation script sets up a network with mobile sensor nodes and uses a simple average hop count algorithm to estimate the positions of the nodes based on the positions of anchor nodes. The positions and estimated positions of the sensor nodes are logged.
Additional Considerations
To extend the functionality of your range-free localization simulation, consider the following:
1. Advanced Localization Algorithms
Implement more advanced range-free localization techniques like DV-Hop, Centroid, or APIT to develop the accuracy of position estimates.
2. Dynamic Network Topologies
Mimic dynamic network topologies where nodes can move, join, or leave the network, and calculate the performance of the localization techniques in such scenarios.
3. Communication Protocols
Incorporate communication protocols to permit nodes to exchange position and connectivity information, which can be used for localization.
4. Performance Metrics
Collect and analyse additional metrics like localization error, network latency, energy consumption, and packet delivery ratio to estimate the performance of the localization approach.
5. Real-World Scenarios
Simulate real-world scenarios such as environmental monitoring, disaster response, or wildlife tracking to test the effectiveness of the range-free localization approach in practical applications.
In conclusion, we had learnt and understood how to implement the range-free localization in ns3 that has used in distance measurements scenarios that were implemented by ns3 framework. Also we offer the all kinds of information regarding the range-free localization.
Feel free to reach out to us for assistance with implementing Range Free Localization in the ns3 tool. Our experts are here to provide you with the best guidance on how to apply it to your project. Additionally, our developers can help you with more project ideas and their execution, including utilizing a wireless sensor network (WSN) to calculate node positions based on connectivity data.