How to Start Satellite Communication Projects Using NS2

To stimulate a Satellite Communication project using NS2 (Network Simulator 2) contains the configuration of appropriate the designs for satellite communication networks. Satellite communications are frequently features through high-latency links, large coverage areas, and detailed broadcast features, such as free-space path loss and signal attenuation due to atmospheric conditions.

While NS2 is commonly more geared near terrestrial wireless networks, it can be extended the replicate of satellite networks through configure a suitable models for the satellite channel, network topology, routing, and mobility of the satellite. We get initialize, follow the steps outlined below:

Steps to Start Satellite Communication Projects Using NS2

  1. Install NS2

Create a certain NS2 is installed on the system. If NS2 is not installed, we can download and install it using the procedures for specific the operating system.

  • For Linux:

sudo apt-get install ns2

  • For macOS/Windows: Deliberate the virtual machine for Linux or installing Cygwin to use NS2 on Windows.

Validate the installation through processing a basic sample for replication script we check the installation process was successful.

  1. Understand Satellite Communication Characteristics

Satellite communication typically involves:

  • Geostationary Orbit (GEO): Satellites in GEO orbit remain stable relative to the Earth’s surface, offers the nonstop coverage for the large area.
  • Low Earth Orbit (LEO): LEO satellites orbit much near to Earth; through low latency nevertheless coverage is further limited and needs the constellations of satellites.
  • Medium Earth Orbit (MEO): These satellites deliver a balance among the GEO and LEO in terms of latency and coverage.

Key considerations:

  • Propagation Delay: Due to the long distance for the satellite and ground stations, broadcast delays are much higher than terrestrial communications.
  • Link Budget: The received signal is power reducing by distance. Factors such as path loss, atmospheric attenuation, and rain fade must be considered.
  • Latency: Satellite connections are generally has higher latency, particularly in GEO systems.
  1. Extend NS2 for Satellite Communication

NS2 does not natively helps for satellite communication; nevertheless there are extensions available for simulating satellite networks. We can either extend NS2 with modify the code or use previous satellite network designs from research repositories.

Here are some options:

  • Satellite Communication Models for NS2: Particular research functions and extensions are offers the design for replicating the satellite communication networks. The General extension is the Satellite Communication Package (SCP) for NS2.
    • Example Repository: Examine the packages such as Satellite NS2 or specific research papers which involve the satellite communication models.
  • Custom Satellite Models: We can apply the satellite communication models from scratch through adjusting broadcast, mobility, and networking parameters.
  1. Set up Satellite Network Topology

The satellite communication project, we want to express the satellite and ground station network, as well as the communication connection.

Define the Topology:

  • Ground Stations: Typically, We would have several ground stations that communicate through satellites in orbit.
  • Satellite Nodes: We can design the satellites either in GEO, LEO, or MEO or replicate a hybrid of these orbits, depending on the replication goals.

Example Topology:

# Create the simulator object

set ns [new Simulator]

# Create ground station nodes

set gs1 [$ns node]

set gs2 [$ns node]

# Create satellite node (GEO, LEO, MEO)

set sat1 [$ns node]

# Set the mobility of ground stations and satellite (static or moving)

$gs1 set X_ 10.0

$gs1 set Y_ 20.0

$gs2 set X_ 100.0

$gs2 set Y_ 200.0

$sat1 set X_ 100.0

$sat1 set Y_ 300.0

$sat1 set Z_ 2000.0   ;# Altitude of satellite

# Define link parameters (bandwidth, delay, etc.)

$ns duplex-link $gs1 $sat1 1Mb 100ms DropTail

$ns duplex-link $sat1 $gs2 1Mb 100ms DropTail

# Set up application layer traffic (e.g., CBR or FTP)

set cbr [new Application/Traffic/CBR]

$cbr attach-agent $gs1

$ns at 1.0 “$cbr start”

$ns at 4.0 “$cbr stop”

# Define energy consumption model for the nodes (if needed)

set energy [new EnergyModel]

$ns attach-energy-model $gs1 $energy

$ns attach-energy-model $gs2 $energy

$ns attach-energy-model $sat1 $energy

# Run the simulation

$ns run

In this example:

  • Ground Stations for instance gs1, gs2 communicate by the satellite such as sat1.
  • Described the mobility nodes, and the links among the detailed such as with bandwidth and delay.
  • The basic CBR traffic generator is used for communication among the nodes.
  1. Satellite Channel Models

Satellite communication connections are impacted through multiple factors such as:

  • Path Loss: The signal attenuates by distance, particularly in satellite communication, due to free-space path loss and atmospheric effects.
  • Delay: The broadcast delay among the satellite and ground stations is significant, particularly for GEO satellites.

We can use standard path loss models or extend for based on requirements.

Example: Path Loss Model in Satellite Communication

Designed for a GEO satellite, we can design the free-space path loss (FSPL) using the following formula:

FSPL=20log⁡10(d)+20log⁡10(f)+20log⁡10(4π/c)\text{FSPL} = 20 \log_{10}(d) + 20 \log_{10}(f) + 20 \log_{10}(4\pi / c)FSPL=20log10​(d)+20log10​(f)+20log10​(4π/c)

Where:

  • ddd is the distance between the satellite and ground station,
  • fff is the frequency of operation,
  • ccc is the speed of light.

In NS2, you can implement the path loss and delay calculation for satellite channels:

# Set the frequency (e.g., L-band, C-band)

set freq 1.5e9   ;# Frequency in Hz

# Set the distance between the ground station and satellite (e.g., GEO satellite at 35,786 km)

set distance 35786000

# Calculate FSPL in dB

set fspl [expr {20 * log10($distance) + 20 * log10($freq) + 20 * log10(4 * 3.14159 / 3e8)}]

# Set the propagation delay (using speed of light)

set delay [expr {$distance / 3e8}]

# Assign the FSPL and delay to the satellite channel

$ns set Propagation/FSPL $fspl

$ns set Propagation/Delay $delay

  1. Energy Consumption Model

In satellite communications, especially in LEO satellites, energy efficiency is crucial. You can simulate the energy consumption of satellite and ground stations by using NS2’s EnergyModel.

Example of energy model:

# Energy model setup

set energyModel [new EnergyModel]

$ns attach-energy-model $gs1 $energyModel

$ns attach-energy-model $gs2 $energyModel

$ns attach-energy-model $sat1 $energyModel

# Set parameters for energy consumption (transmission power, idle power, etc.)

$energyModel set tx-power_ 0.5    ;# Transmission power in watts

$energyModel set rx-power_ 0.4    ;# Reception power in watts

$energyModel set idle-power_ 0.05 ;# Idle power in watts

  1. Traffic Generation and Routing

Intended for satellite communication, we require creating congestion among the ground stations or between a ground station and a satellite. We can use:

  • CBR (Constant Bit Rate) it includes the congestion for simple validations.
  • TCP or FTP Congestion to replicate the further realistic file transfers.

Example of setting up CBR traffic:

# CBR Traffic between ground station 1 and satellite

set cbr [new Application/Traffic/CBR]

$cbr attach-agent $gs1

$ns at 2.0 “$cbr start”

$ns at 5.0 “$cbr stop”

  1. Mobility Models

We can replicate the satellite mobility in LEO or MEO or generate further complex mobility models for the satellites. If we need to replicate the action for satellites in orbit, you would require modelling the orbital mechanics.

Designed for LEO satellites, we can define an orbital trajectory or use a simple circular path to replicate their action.

Example of simple mobility for LEO satellites:

# Set a simple circular trajectory for the satellite (simplified model)

$sat1 random-motion

  1. Run the Simulation

Next configure the topology, mobility, propagation, and traffic models; we can process for the replication using the following command:

ns satellite_comm.tcl

The outcomes will be written into trace files, that can examine the tools like AWK, XGraph, or NS2’s trace tools. Analyze the parameter metrics like as throughput, latency, packet loss, and energy consumption.

  1. Extend the Simulation

After we have the simple satellite communication setting the process, we can extend the replication through:

  • Executing the satellite routing protocols such as SATP (Satellite Ad-hoc Transport Protocol) or DART.
  • Discovering the constellations of satellites for improve the coverage for instance especially in LEO systems.
  • Employing the handovers among the satellites or ground stations are the actions.
  • Replicating the different channel models, like as rain fade or atmospheric attenuation.

Conclusion

Starting a Satellite Communication project in NS2 involves defining a suitable network topology with satellites and ground stations, setting up appropriate communication links, and implementing energy and propagation models. Since NS2 doesn’t have native satellite communication support, you need to extend it with existing modules or custom code. By simulating different types of satellites (GEO, LEO, MEO), traffic patterns, and energy models, you can analyze the performance of satellite networks in various scenarios.

With this configuration, we can exhaustively make you understand the implementation steps of offered example regarding Satellite communication using ns2 simulator tools. For further queries regarding this manual, we will resolve it over another manual.