How to Implement Network Multi RAT in NS2

To implement a multi-RAT (Radio Access Technology) network has require to include, simulating several radio technologies such as Wi-Fi, LTE, 5G, and so on in a heterogeneous network environment within NS2. This network scenarios are frequently used to handle the devices including various connectivity choices and also permits the handover among technologies for enhanced these performance or coverage. The given demonstration will guide you through the implementation network multi RAT in ns2:

Key Concepts in Multi-RAT Network Implementation:

  1. Multiple Radio Technologies: To replicate various wireless technologies like Wi-Fi (IEEE 802.11), LTE, or 5G.
  2. Heterogeneous Network: These nodes can communicate through several technologies, either choosing the most suitable one according to the conditions or switching actively.
  3. Handover Mechanisms: Mimic the handover from one RAT to another to make sure continuous service as conditions change.

Steps to Implement Multi-RAT Network in NS2

  1. Install NS2

Make sure that NS2 is installed on the machine then we can download and install NS2 from here. The simulation NS2 does not natively support LTE or 5G, however including an external modules such as LENA (for LTE) or custom implementations, we can mimic multiple RATs. Wi-Fi is supported natively.

  1. Simulate a Multi-RAT Network

The simple approach is to emulate various RATs like Wi-Fi and LTE as isolated networks and handle the node movement or handover among them.

For this specimen, we will replicate a basic multi-RAT network including Wi-Fi and a generic cellular network. This TCL script will setup various RATs and permit a node to handover among them.

  1. Create a TCL Script for Multi-RAT Simulation

Example: Simulating Wi-Fi and Cellular Network (LTE Placeholder)

# Define a simulator object

set ns [new Simulator]

# Define trace and nam files for output

set tracefile [open out.tr w]

set namfile [open out.nam w]

$ns trace-all $tracefile

$ns namtrace-all $namfile

# Define a ‘finish’ procedure

proc finish {} {

global ns tracefile namfile

$ns flush-trace

close $tracefile

close $namfile

exec nam out.nam &

exit 0

}

# Setup node configurations for Wi-Fi and Cellular (LTE Placeholder)

$ns node-config -adhocRouting DSDV -llType LL -macType Mac/802_11 -ifqType Queue/DropTail/PriQueue \

-ifqLen 50 -antType Antenna/OmniAntenna -propType Propagation/TwoRayGround -phyType Phy/WirelessPhy

# Create nodes (assume n0 connects via Wi-Fi and n1 via cellular)

set n0 [$ns node]

set n1 [$ns node]

set n2 [$ns node]  ;# Node that supports both RATs (handover node)

# Define topography object

set topo [new Topography]

$topo load_flatgrid 500 500

# Create Wi-Fi Network for nodes n0 and n2

$ns wireless-channel-config -channelType Channel/WirelessChannel

$ns duplex-link $n0 $n2 11Mb 10ms DropTail

$ns duplex-link $n2 $n1 11Mb 10ms DropTail

# Create Cellular Network for nodes n1 and n2

# (Placeholder: Cellular RAT will be simulated as a wired link with cellular-like properties)

$ns duplex-link $n1 $n2 50Mb 5ms DropTail   ;# Simulate LTE/5G link as a wired link

# Define traffic sources (Wi-Fi TCP, Cellular UDP)

set tcp [new Agent/TCP]

set sink [new Agent/TCPSink]

$ns attach-agent $n0 $tcp

$ns attach-agent $n1 $sink

$ns connect $tcp $sink

# TCP traffic over Wi-Fi

set ftp [new Application/FTP]

$ftp attach-agent $tcp

$ftp start 1.0

$ftp stop 4.0

# Simulate UDP traffic over Cellular Network (n2 to n1)

set udp [new Agent/UDP]

set null [new Agent/Null]

$ns attach-agent $n2 $udp

$ns attach-agent $n1 $null

$ns connect $udp $null

set cbr [new Application/Traffic/CBR]

$cbr attach-agent $udp

$cbr set packetSize_ 512

$cbr set rate_ 10Mb

$cbr start 1.0

$cbr stop 5.0

# Mobility for Node n2: Starts in Wi-Fi range and hands over to Cellular

$ns at 2.5 “$n2 set X_ 300; $n2 set Y_ 200; $n2 set Z_ 0”

$ns at 4.0 “$n2 set X_ 500; $n2 set Y_ 500; $n2 set Z_ 0”  ;# Move n2 to Cellular network

# Define the simulation end

$ns at 5.0 “finish”

# Run the simulation

$ns run

  1. Explanation of the Script
  • Node Configuration: The network is set up to replicate both Wi-Fi and a generic cellular RAT are using a wired link to represent LTE/5G. The nodes n0 and n2 are use Wi-Fi primarily when the nodes n1 and n2 use a faster cellular network.
  • Traffic Types: The TCP traffic is produced across the Wi-Fi when UDP traffic is forward across the cellular RAT (simulated as a high-bandwidth link).
  • Handover Simulation: These node n2 begins in Wi-Fi coverage and transfer into the cellular RAT area at time 4.0 that replicating handover among the Wi-Fi and cellular.
  1. Handover Mechanisms

The handover among RATs can be replicated using the mobility models. In this script, the node n2 transfers from Wi-Fi to Cellular. We can also mimic vertical handover by observing signal strength or network conditions. However this needs more difficult logic and extra custom code.

Vertical Handover Example (Basic):

# Pseudo-code for vertical handover

proc vertical_handover {node src dest} {

set rssi [measure_signal_strength $node]

if { $rssi < threshold } {

switch_to_network $node $dest

} else {

continue_on_current_network $node $src

}

}

# At each timestep, check for handover conditions

$ns at 1.0 “vertical_handover $n2 Wi-Fi Cellular”

In a comprehensive execution, we could execute the signal strength measurement and switching logic among various RATs.

  1. Run the Simulation

We can run the simulation, save the script with a .tcl extension such as multi_rat.tcl, then run it in NS2 with:

ns multi_rat.tcl

  1. Analyse the Results
  • Trace File (out.tr): Evaluate the trace file for packet transmission, handover events, and traffic flow.
  • NAM File (out.nam): Open the NAM file to envision node movement, RAT transitions, and traffic flow.

nam out.nam

  1. Performance Metrics

We can estimate the performance of the multi-RAT network by measuring:

  • Throughput: Liken throughput before and after handover.
  • Delay: Compute the delay while switching among Wi-Fi and Cellular.
  • Packet Loss: Verify for packet loss when the handover period.
  • Jitter: Calculate jitter, particularly for real-time traffic such as VoIP or video streams.

Extending the Multi-RAT Simulation

We can further improve the simulation by:

  1. Introducing Realistic RAT Models: We can use a custom LTE/5G module like LENA for LTE or make custom radio technologies.
  2. Advanced Handover Mechanisms: Execute signal strength-based handover or load-based handover to choose the optimal RAT.
  3. QoS Management: Execute QoS policies for the various RATs to make certain that high-priority traffic obtains the essential resources.

Conclusion

Replicating a Multi-RAT network within NS2 has needs to include, setup several radio technologies (Wi-Fi, Cellular) and mimicking handover among them. By setting up mobility and launching various traffic types, we learn how handover impacts network performance and QoS metrics.

This Technique will walk you via the comprehensive implementation process of Network Multi RAT with their specimens using the simulation ns2 tool. We will also provide the additional data on this topic, if you needed for the future enhancements.

Get help with Network Multi RAT project using ns2tool implementation, feel free to reach ns2project.com. We provide implementation guidance with high quality results.