To simulate Light Fidelity (LiFi) projects in NS2 have includes designing the communication among devices using visible light rather than traditional RF signals such as WiFi. While NS2 is mainly intended for replicating radio-based networks such as WiFi, cellular, and ad-hoc networks, we will required to expand its functionality or adapt existing modules to replicate LiFi communication. A key characteristic of LiFi networks has involves line-of-sight (LOS) communication, high-speed data transmission, and interference management when multiple light sources are present.
Since NS2 does not directly support LiFi, we can replicate LiFi networks by adapting the wireless communication models, using custom propagation models, and set up appropriate mobility, traffic, and data transmission behaviours. Submit all the details of your LiFi projects to phdprime.com, and we will assist you with a comprehensive explanation. We specialize in simulating LiFi projects using the ns2 tool tailored to your project, and we also provide top project topics in your area of interest. Receive guidance on replicating radio-based networks like WiFi, cellular, and ad-hoc networks from our technical experts related to your work.
Here is a step-by-step guide to simulate LiFi projects in NS2:
Steps to Simulate LiFi Projects Using NS2
- Install NS2:
Make sure that NS2 is installed and processing on system. To simulate LiFi, we want to adapt the underlying C++ code for wireless communication to reflect the properties of visible light communication.
- Define the Network Topology for LiFi:
In a usual LiFi network, LiFi Access Points (APs) serve as transmitters (LEDs), and user devices are receivers. The devices interact by using light, with the APs enlightening a certain coverage area.
Example of defining a basic LiFi network topology:
set ns [new Simulator]
# Define LiFi access points (APs) and user devices (receivers)
set lifiAP1 [$ns node]
set device1 [$ns node]
set device2 [$ns node]
# Create a server (for internet access)
set server [$ns node]
# Set up links between the LiFi APs and the server
$ns duplex-link $lifiAP1 $server 10Mb 10ms DropTail
- Customize Wireless Propagation Model for LiFi:
While LiFi utilize light for communication, the wireless propagation model must reflect the characteristics of visible light. In LiFi networks, Line-of-Sight (LOS) is needed for communication, and obstacles can block signals. We will requires to adjust the TwoRayGround propagation model or execute a custom model to reflect light behaviour.
Example of using a customized propagation model:
# Use a custom propagation model for LiFi (requires modification in NS2 code)
Phy/WirelessPhy set freq_ 4.3e14 ;# Frequency for visible light (in Hz)
Phy/WirelessPhy set RXThresh_ 1.0e-10
Phy/WirelessPhy set CSThresh_ 1.0e-9
Phy/WirelessPhy set L_ 1.0
- Set Up Communication Protocols:
We can utilize standard UDP or TCP communication protocols to replicate the data transmission among LiFi devices. For real-time data like video streaming, UDP can be used, since TCP is better for reliable data transmission.
Example of configuring UDP communication among a LiFi device and the server:
# Use UDP agents for data transmission from device1 to the server
set udp1 [new Agent/UDP]
set null1 [new Agent/Null]
$ns attach-agent $device1 $udp1
$ns attach-agent $server $null1
$ns connect $udp1 $null1
# Similarly configure for device2
- Simulate LiFi Traffic (High-Speed Data Transmission):
LiFi is known for its high-speed data transmission capabilities. We can replicate this by creating traffic with high data rates using CBR (Constant Bit Rate) or other traffic models to replicate data transmission over LiFi.
Example of generating high-speed LiFi traffic:
# Simulate video streaming from device1 to the server (via LiFi AP)
set cbr1 [new Application/Traffic/CBR]
$cbr1 set packetSize_ 1024 ;# Packet size in bytes
$cbr1 set interval_ 0.01 ;# Send one packet every 10 ms (100 packets per second)
$cbr1 attach-agent $udp1
- Implement Mobility Models for LiFi Users (Optional):
LiFi users are usually stationary or have limited mobility because of the line-of-sight requirement. But, if users move inside a room or among different rooms (with different LiFi APs), we can simulate this mobility.
Example of simulating mobility for LiFi users:
# Generate random waypoint mobility for LiFi devices
setdest -n 2 -p 0.0 -s 5 -t 100 -x 1000 -y 1000 > mobility.tcl
source mobility.tcl
This models users moving slowly (speed 5 m/s) within a 1000×1000 meter area.
- Implement Handover Mechanism Between LiFi APs (Optional):
In a LiFi network, users’ needs to move out of the range of one LiFi AP and into the range of another, requiring a handover process to sustain connectivity. We can replicate this by monitoring the signal strength (or LOS condition) and transmitting the connection to the next AP when needed.
Example of simulating a handover mechanism:
# Define a simple handover process between LiFi APs
Class LiFiHandover {
procedure checkSignalStrength {node AP1 AP2} {
set signalStrength [measureSignalStrength $node $AP1]
if {$signalStrength < 0.1} { ;# Threshold for signal strength
puts “Handover from AP1 to AP2”
$this connectToAP $AP2
}
}
procedure measureSignalStrength {node AP} {
# Custom logic to measure signal strength
return 0.5 ;# Placeholder value
}
procedure connectToAP {AP} {
# Custom logic to connect the node to the new AP
}
}
- Simulate Interference and Shadowing (Optional):
In LiFi networks, multiple light sources can cause interference, and problems can bottleneck the signal. We can replicate this by establishing interference models and shadowing impacts in the communication model.
Example of adding interference and shadowing effects:
Phy/WirelessPhy set shadowingModel_ ShadowingModel
Phy/WirelessPhy set shadowingValue_ 1.0e-3 ;# Adjust the shadowing factor
# Implement interference logic in the propagation model (requires C++ modification)
- Run the Simulation:
After configuring the LiFi network, traffic, and mobility, we can execute the simulation using NS2.
Example of running the simulation:
ns lifi_simulation.tcl
We can envision the network using NAM (Network Animator) to monitor on how the LiFi devices interact with the server and how mobility or handovers happens:
nam lifi_simulation.nam
- Analyse the Results:
After the simulation, we need to evaluate the performance of LiFi network by extracting parameters from the trace file (*.tr). Key parameters to evaluate to contain:
- Throughput: Evaluate the amount of data successfully routed over LiFi.
- Packet Delivery Ratio (PDR): Assess the percentage of packets successfully delivered.
- Latency: Measure the delay in delivering data, especially for real-time applications.
- Interference Effects: Evaluate how interference impacts the quality of the LiFi signal.
- Handover Latency: Assess the time taken for a successful handover among LiFi APs.
we can utilize AWK or Python scripts to process the trace file and estimate these parameters.
Example of evaluating throughput using AWK:
awk ‘{if ($1==”r” && $4==”AGT” && $7==”CBR”) print $0}’ lifi_simulation.tr
- Advanced Features (Optional):
- Multicast/Broadcast Traffic: Mimic multicast or broadcast traffic for scenarios such as indoor multimedia streaming using LiFi.
- Security Mechanisms: Execute security features such as encryption or authentication for secure LiFi communication.
- LiFi-WiFi Heterogeneous Networks: Mimic a hybrid LiFi-WiFi network in which the users switch among LiFi and WiFi according to their location or the quality of the connection.
In this manual, we explore the complete guide on get started the Light Fidelity in ns2 analysis tool and it is used for communication over the network. We also provide the key characteristics and the sample code snippets to execute the simulation. More information will be shared in another manual.
