How to Implement Satellite Constellations 5G in NS2

To implement satellite constellations for 5G networks in NS2 has need to expand NS2’s simple functionalities meanwhile it does not natively support satellite communications or 5G technologies out of the box. Executing satellite constellations for 5G has contains to modelling the orbital dynamics, inter-satellite communication, ground-to-satellite links, and the combined of 5G characteristics such as ultra-reliable low-latency communications (URLLC) and enhanced mobile broadband (eMBB). The below is guide on how to implement simple satellite constellations for 5G networks in NS2:

Steps to Implement Satellite Constellations for 5G in NS2:

  1. Understand the Basics of Satellite Constellations and 5G:
  • Satellite Constellation: A group of satellites working together to deliver continuous coverage over a region or globally like Starlink, OneWeb. These satellites can interact with each other (inter-satellite links) and with ground stations.
  • 5G Requirements: 5G has three main service classes: enhanced mobile broadband (eMBB), ultra-reliable low-latency communication (URLLC), and massive machine-type communications (mMTC). The implementation should manage these service requirements.
  1. Modify NS2 for Satellite Network Support:

NS2 does not come with built-in satellite support; however we can extend it by:

  • Modeling Satellite Nodes: generate satellite nodes in NS2 by describing them as mobile nodes nevertheless with particular orbital trajectories. We need to adjust node mobility to follow satellite orbits.
  • Inter-Satellite Links: Execute a routing protocol that permits an inter-satellite communication.
  • Ground Stations: Treat ground stations as static nodes that interact with satellites and serve as gateways to the terrestrial network.
  1. Satellite Mobility Model:

Satellites move in predefined orbits. We can design this in NS2 by adjusting the mobility model of nodes to follow a circular or elliptical path around the Earth.

We can generate a custom mobility model in C++ to mimic an orbital motion. For example:

// Simulating orbital movement for satellite nodes

void SatelliteMobility::updatePosition(double time) {

// Calculate satellite position based on orbital parameters

double altitude = 550;  // Altitude in km for low Earth orbit (LEO)

double inclination = 53; // Orbit inclination in degrees

double angular_velocity = sqrt(G * EARTH_MASS / pow(altitude + EARTH_RADIUS, 3));  // Kepler’s law

// Update satellite position

position.x = cos(angular_velocity * time) * (altitude + EARTH_RADIUS);

position.y = sin(angular_velocity * time) * (altitude + EARTH_RADIUS) * cos(inclination);

}

  • We will need to intermittently update the satellite’s position according to orbital dynamics.
  1. Inter-Satellite and Ground-to-Satellite Links:
  • Use a wireless channel to model satellite communication links.
  • For inter-satellite communication, adjust the MAC layer to manage long-distance communication delays and adapt the transmission range of satellite nodes.

In the Tcl script:

set ns [new Simulator]

# Define a wireless channel for inter-satellite communication

set wireless_channel [new Channel/WirelessChannel]

# Create satellites and ground stations

set satellite1 [$ns node]

set satellite2 [$ns node]

set ground_station [$ns node]

# Set wireless interfaces for satellites

$satellite1 set channel_ $wireless_channel

$satellite2 set channel_ $wireless_channel

$ground_station set channel_ $wireless_channel

# Define mobility for satellites (custom mobility model for orbits)

$satellite1 set mobility_ “SatelliteMobility”

$satellite2 set mobility_ “SatelliteMobility”

  1. Routing Protocol for Satellite Networks:

Adjust or execute a routing protocol to manage satellite networks. Satellite networks usually use dynamic routing because of the mobility of satellites. We can expand an existing protocol (such as AODV or DSR) to help the satellite-specific parameters such as delay, bandwidth, and handover management.

  • Handover Mechanism: Satellites will move out of the range of ground stations, so handover among satellites must be executed to make sure continuous connectivity.
  • Delay-Tolerant Routing (DTN): For satellite networks, routing protocols such as DTN can be supportive in scenarios where there are high latency and frequent disconnections.
  1. 5G Traffic Modeling:
  • Traffic Types: To mimic numerous types of 5G traffic such as eMBB (high bandwidth, video streaming), URLLC (low-latency, real-time control), and mMTC (massive IoT).
  • Use correct traffic models for each type of service. For instance, for eMBB, use a CBR (Constant Bit Rate) application to mimic high-bandwidth video traffic.

Example for multimedia traffic (eMBB):

set udp [new Agent/UDP]

set null [new Agent/Null]

set cbr [new Application/Traffic/CBR]

$ns attach-agent $satellite1 $udp

$ns attach-agent $ground_station $null

$cbr attach-agent $udp

$cbr set packetSize_ 1500

$cbr set rate_ 5Mb

$ns connect $udp $null

  1. 5G Service Classes Integration:

We can execute numeros 5G service classes (eMBB, URLLC, mMTC) by:

  • Modifying QoS Parameters: Adapt parameters such as bandwidth, delay, and reliability for each type of traffic.
  • Traffic Prioritization: execute mechanisms at the MAC layer to select numerous traffic types such as URLLC traffic will have higher priority over eMBB.
  1. Tcl Simulation Script for Satellite Constellation and 5G Integrations:

# Create a simulator instance

set ns [new Simulator]

# Create wireless channel for satellite communication

set wireless_channel [new Channel/WirelessChannel]

# Define satellite nodes

set satellite1 [$ns node]

set satellite2 [$ns node]

set satellite3 [$ns node]

# Define ground stations

set ground_station1 [$ns node]

set ground_station2 [$ns node]

# Assign wireless channel to nodes

$satellite1 set channel_ $wireless_channel

$satellite2 set channel_ $wireless_channel

$satellite3 set channel_ $wireless_channel

$ground_station1 set channel_ $wireless_channel

$ground_station2 set channel_ $wireless_channel

# Set mobility model (custom satellite mobility for constellation)

$satellite1 set mobility_ “SatelliteMobility”

$satellite2 set mobility_ “SatelliteMobility”

$satellite3 set mobility_ “SatelliteMobility”

# Create UDP agent and CBR traffic for eMBB simulation

set udp1 [new Agent/UDP]

set null1 [new Agent/Null]

$ns attach-agent $satellite1 $udp1

$ns attach-agent $ground_station1 $null1

set cbr [new Application/Traffic/CBR]

$cbr attach-agent $udp1

$cbr set packetSize_ 1500

$cbr set rate_ 5Mb  ;# eMBB traffic rate

$ns connect $udp1 $null1

# Start simulation

$ns at 1.0 “$cbr start”

$ns at 100.0 “finish”

$ns run

  1. Analysis and Validation:
  • Gather parameters such as throughput, latency, packet delivery ratio, and handover success rate.
  • Use trace files to evaluate the performance of the satellite constellation with 5G traffic.

Finally, we clearly aggregated and explained the complete procedures on how to execute the satellite constellation in 5G network and also we provide the sample snippet to implement the simulation in ns2 simulation tool. We will also explain the novel approaches to executing the satellite constellation in 5G network across multiple simulations.  To set up 5G satellite constellations in the NS2 tool, reach out to the ns2project.com team for personalized help. We offer great project ideas, topics, and network comparison results.