How to Implement LiFi in ns2

To implement the Li-Fi (Light Fidelity) in ns2 (Network Simulator 2) which is very difficult because of ns2 mainly concentrates on RF (Radio Frequency) communication and does not back optical communication mechanisms like Li-Fi. Yet, you can compute a Li-Fi network by replicating vital properties of optical communication like high-speed, line-of-sight communication, and narrow range. Follow the demonstration guide to get started with the implementation process:

Step-by-Step Implementation:

Conceptual Overview

In a Li-Fi network:

  1. Li-Fi Access Points (APs): These are the light sources (e.g., LEDs) that offer high-speed data interaction to devices inside their line of sight.
  2. Li-Fi Devices: Devices that obtains data from Li-Fi APs, usually inside the restricted range and line of sight.
  3. Communication Characteristics: Li-Fi networks commonly have high data rates, narrow coverage area, and need line-of-sight communication.

Step 1: Conceptualize the Li-Fi Simulation

In this simulation, we will set up a basic Li-Fi environment where Li-Fi AP interacts with several devices and will simulate the properties of Li-Fi included limited range and high data rates by modifying the parameters like transmission power and distance.

Step 2: Create the Tcl Script

Follow the below example Tcl script that simulates a basic Li-Fi network scenario in ns2.

Example Tcl Script for Simulating Li-Fi in ns2

# Create a simulator object

set ns [new Simulator]

 

# Define the topography object (for a small area to simulate Li-Fi coverage)

set topo [new Topography]

$topo load_flatgrid 100 100  # 100m x 100m area

# Create the General Operations Director (GOD) for wireless simulations

create-god 4  # Number of nodes (3 devices + 1 Li-Fi AP)

# Configure the nodes for the Li-Fi network

$ns node-config -llType LL \

-macType Mac/802_11 \

-ifqType Queue/DropTail/PriQueue \

-ifqLen 50 \

-antType Antenna/OmniAntenna \

-propType Propagation/FreeSpace \

-phyType Phy/WirelessPhy \

-channelType Channel/WirelessChannel \

-topoInstance $topo \

-agentTrace ON \

-routerTrace ON \

-macTrace ON \

-movementTrace OFF

# Open trace and NAM files for recording the simulation

set tracefile [open lifi_out.tr w]

$ns trace-all $tracefile

set namfile [open lifi_out.nam w]

$ns namtrace-all-wireless $namfile 100 100

# Define a finish procedure to close files and end the simulation

proc finish {} {

global ns tracefile namfile

$ns flush-trace

close $tracefile

close $namfile

exec nam lifi_out.nam &

exit 0

}

# Create Li-Fi Access Point (AP) and device nodes

set ap [$ns node]

set device1 [$ns node]

set device2 [$ns node]

set device3 [$ns node]

# Set initial positions for the Li-Fi AP and devices (to simulate line of sight)

$ap set X_ 50.0

$ap set Y_ 50.0

$ap set Z_ 0.0

$device1 set X_ 30.0

$device1 set Y_ 50.0

$device1 set Z_ 0.0

$device2 set X_ 50.0

$device2 set Y_ 70.0

$device2 set Z_ 0.0

$device3 set X_ 70.0

$device3 set Y_ 50.0

$device3 set Z_ 0.0

# Define a custom procedure for simulating Li-Fi communication

proc send_lifi_data {src dst packetSize rate} {

global ns

# Create a UDP agent to simulate Li-Fi data traffic

set udp [new Agent/UDP]

$ns attach-agent $src $udp

set null [new Agent/Null]

$ns attach-agent $dst $null

$ns connect $udp $null

# Generate high-speed Li-Fi data traffic using a CBR application

set cbr [new Application/Traffic/CBR]

$cbr attach-agent $udp

$cbr set packetSize_ $packetSize

$cbr set rate_ $rate

$cbr start

}

# Simulate Li-Fi data transmission from the AP to the devices

$ns at 1.0 “send_lifi_data $ap $device1 1024 1Gb”

$ns at 3.0 “send_lifi_data $ap $device2 1024 1Gb”

$ns at 5.0 “send_lifi_data $ap $device3 1024 1Gb”

# Schedule the end of the simulation

$ns at 10.0 “finish”

# Run the simulation

$ns run

Step 3: Run the Tcl Script

Save the script with a .tcl extension, for instance, lifi_simulation.tcl. Then, execute the script using the given command in your terminal:

ns lifi_simulation.tcl

Step 4: Visualize the Simulation

To visualize the simulation, open the created NAM file using:

nam lifi_out.nam

Script Explanation

  • Li-Fi Access Point (AP): The ap node denotes a Li-Fi AP, which transfers data to the devices.
  • Devices: The nodes device1, device2, and device3 indicated devices that gets data from the Li-Fi AP.
  • Li-Fi Characteristics: The script replicated Li-Fi communication by using high data rates and placing devices inside a limited area to signify the line-of-sight and short-range properties of Li-Fi.

Customization

  • Mobility: Execute mobility models to replicate devices travelling in and out of the Li-Fi AP’s exposure area.
  • Different Traffic Types: Examine with various types of traffic (like video streaming, file transfer) to mimic several Li-Fi use cases.
  • Multiple APs: Attach numerous APs to simulate a more sophisticated Li-Fi network with handovers or overlapping exposure areas.
  • Channel Model: Adjust the propagation model to imitate many environmental conditions like hindrances that may influence the line of sight.

Limitations

  • Simplified Li-Fi Model: This script offers a simple computation of Li-Fi communication and does not fully cover the optical assets or threats like light intrusion, ambient light, or the influence of physical obstructions.
  • No Physical Layer Simulation: It can’t simulate the physical layer characteristics certain to the optical communication which is light wavelength, modulation methods or the impacts of ambient light.
  • Limited Protocol Support: ns2 is not configured for optical communication protocols, so the simulation is narrow to estimating Li-Fi using available wireless communication models.

In conclusion, we learned the overall detail that is a must to understand the Lifi and their implementation, customization including their restriction in the Network simulator 2 (ns2). We will provide the extra information of Lifi or ns2 in case you need them.

Implementation of  LiFi in ns2 are done in a structured way by our developers we have the leading tools and resources to get your work done on high quality.