How to Implement Low earth orbit satellite in OMNeT++

To implement the Low Earth Orbit (LEO) Satellite Networks in OMNeT++, we have to simulate network of satellites in low earth orbit which interact with one another and also with ground station. These networks are used for global communication services, internet coverage and earth observation. Approach omnet-manual.com we offer best network performance analysis assistance. In the following, we deliver the step-by-step guide to implementing LEO satellite networks in OMNeT++.

Step-by-Step Implementation:

Define the LEO Satellite Network Architecture

Satellites: Indicates the LEO satellites orbiting the Earth and using inter-satellite links (ISLs) to communicate with each other and with ground stations.
Ground Stations: Denotes the nodes on Earth that communicate with satellites.
Inter-Satellite Links (ISLs): Signifies the optical or radio frequency communication links amongst satellites.
Satellite-to-Ground Links: Represent the communication links amongst satellites and ground stations.

Create OMNeT++ Modules for Satellites, Ground Stations, and Links

Satellite Module: Indicates a satellite node capable of transmitting and receiving signals from other satellites and ground stations.
Ground Station Module: Represents a ground station skilled of communicating with satellites.
Link Modules (ISL and Ground Links): Simulate the communication links amongst satellites and amidst satellites and ground stations.

Example: Satellite Module

simple Satellite {

gates:

inout radioIn[4]; // For communication with other satellites (ISLs)

inout groundIn[2]; // For communication with ground stations

parameters:

double altitude @unit(“km”) = default(500); // Satellite altitude

double speed @unit(“km/s”) = default(7.8); // Orbital speed

@display(“i=device/satellite”);

}

Example: Ground Station Module

simple GroundStation {

gates:

inout groundOut; // For communication with satellites

parameters:

@display(“i=device/groundstation”);

}

Example: Inter-Satellite Link (ISL) Module

simple InterSatelliteLink {

parameters:

double distance @unit(“km”) = default(1000); // Distance between satellites

double dataRate @unit(“Gbps”) = default(10); // Data rate of the ISL

double latency @unit(“ms”) = default(5); // Latency for the signal to travel the distance

gates:

in linkIn; // Input from one satellite

out linkOut; // Output to another satellite

}

Example: Satellite-to-Ground Link Module

simple SatToGroundLink {

parameters:

double distance @unit(“km”) = default(500); // Distance from satellite to ground station

double dataRate @unit(“Gbps”) = default(10); // Data rate of the link

double latency @unit(“ms”) = default(2); // Latency for the signal to travel the distance

gates:

in linkIn; // Input from satellite

out linkOut; // Output to ground station

}

Implement the Internal Logic of Each Component

Satellite Logic: Manage the transmission and reception of signals from other satellites and ground stations. Also, handle the satellite’s movement in orbit.
Ground Station Logic: Manage communication with satellites, containing sending and receiving data.
Link Logic: Simulate the transmission of data over the links, including managing the latency and any signal attenuation.

Example: Satellite Logic in C++

#include <omnetpp.h>

class Satellite : public omnetpp::cSimpleModule {

protected:

virtual void handleMessage(omnetpp::cMessage *msg) override;

virtual void initialize() override;

void updatePosition(); // Method to update satellite position in orbit

double altitude;

double speed;

};

Define_Module(Satellite);

void Satellite::initialize() {

altitude = par(“altitude”);

speed = par(“speed”);

// Schedule the first position update

scheduleAt(simTime() + 1.0, new cMessage(“updatePosition”));

}

void Satellite::handleMessage(omnetpp::cMessage *msg) {

if (strcmp(msg->getName(), “updatePosition”) == 0) {

updatePosition();

scheduleAt(simTime() + 1.0, msg); // Schedule the next position update

} else if (strcmp(msg->getName(), “radioData”) == 0) {

// Handle data received from another satellite or ground station

send(msg, “radioIn$o”, 0); // Example: forward to the first ISL

} else {

// Handle other types of messages, if any

}

void Satellite::updatePosition() {

// Logic to update the satellite’s position based on orbital mechanics

// This could involve changing altitude, calculating new positions, etc.

EV << “Satellite position updated.\n”;

}

Example: Inter-Satellite Link Logic in C++

#include <omnetpp.h>

class InterSatelliteLink : public omnetpp::cSimpleModule {

protected:

virtual void handleMessage(omnetpp::cMessage *msg) override;

virtual void initialize() override;

double distance;

double dataRate;

double latency;

};

Define_Module(InterSatelliteLink);

void InterSatelliteLink::initialize() {

distance = par(“distance”);

dataRate = par(“dataRate”);

latency = par(“latency”);

}

void InterSatelliteLink::handleMessage(omnetpp::cMessage *msg) {

// Simulate transmission delay based on distance and latency

sendDelayed(msg, latency, “linkOut”);

}

Integrate the Components in a NED File

Define the network topology, linking satellites with ISLs and satellites to ground stations.
Mention the locations and movements of the satellites to model the LEO network’s dynamics.

Example: LEO Satellite Network Topology in NED

network LEOSatelliteNetwork {

submodules:

satelliteA: Satellite {

parameters:

altitude = 500;

speed = 7.8;

}

satelliteB: Satellite {

parameters:

altitude = 500;

speed = 7.8;

}

groundStation: GroundStation;

linkAB: InterSatelliteLink {

parameters:

distance = 1000; // Distance between satelliteA and satelliteB

dataRate = 10Gbps;

latency = 5ms;

}

linkAG: SatToGroundLink {

parameters:

distance = 500; // Distance between satelliteA and groundStation

dataRate = 10Gbps;

latency = 2ms;

}

connections allowunconnected:

satelliteA.radioIn[0] –> linkAB.linkIn;

linkAB.linkOut –> satelliteB.radioIn[0];

satelliteA.groundIn[0] –> linkAG.linkIn;

linkAG.linkOut –> groundStation.groundOut;

}

Simulate and Analyze the LEO Satellite Network

Compile: Make certain that all modules are compiled in OMNeT++.
Execute: Run the simulation to monitor how data is transmitted amongst satellites and amidst satellites and ground stations.
Analyze: Use OMNeT++ tools to assess the network’s performance like latency, throughput, handover between satellites, and signal quality.

Advanced Features

Dynamic Topology: Execute logic to simulate the movement of satellites, varying distances and link latencies dynamically as the satellites orbit.
Handover Management: Implement handover mechanisms as they a ground station switches its connection from one satellite to another.
Routing Protocols: Implement routing algorithms for data transmission in the satellite network, consider the dynamic topology.

Example: Handover Management and Routing

Handover Logic: Execute logic in the ground station to switch connections to the close satellite as the satellites move in their orbits.
Routing Algorithm: Implement a routing algorithm in the satellites that dynamically fine-tuning routes based on the varying network topology.

Example: Handover Logic in Ground Station

void GroundStation::handleMessage(omnetpp::cMessage *msg) {

if (strcmp(msg->getName(), “handover”) == 0) {

// Logic to handover communication to a different satellite

int nearestSatelliteIndex = 0; // Example: choose the nearest satellite

send(msg, “groundOut”, nearestSatelliteIndex);

} else {

// Normal message handling

send(msg, “groundOut”);

}

In conclusion, it will help to improve your knowledge about Low Earth Orbit Satellite Networks using the OMNeT++ including how to define the architecture and how to execute the modules for elements in the network with examples. Nevertheless, we can also offer you anything regarding this topic.