How to Implement Network Path planning AUV in NS2

To implement Network Path Planning for Autonomous Underwater Vehicles (AUVs) in NS2, we need to mimic a network in which AUVs are nodes that interact with each other and follow a planned path in an underwater environment. Path planning has includes to generate an optimal route for the AUV to follow, every so often taking into account factors such as energy consumption, network connectivity, and evading difficulties in the underwater terrain.

In NS2, we can replicate the path planning process for AUVs by configuring the movement of AUV nodes in a 2D or 3D underwater environment and allows the communication among the AUVs.

Below are the procedures to implement the network path planning for AUV in ns2:

Key Steps to Implement Network Path Planning for AUVs in NS2:

  1. Set up the Underwater Network Topology: Generate nodes that denotes the AUVs and introduce communication links among them.
  2. Define the Path for AUVs: Program the AUVs to follow the particular paths using the setdest command to describe their movements.
  3. Enable Communication Between AUVs: configure interaction between AUVs using appropriate routing protocols and transmission settings that mimic underwater communications.
  4. Implement Path Planning Logic: Describe the optimal path for each AUV that could be enthusiastically adapted during the simulation.

Step-by-Step Implementation:

  1. Set up the Underwater Network Topology

Initially, describe the network topology by generating nodes that denotes the AUVs. These nodes will move in a defined 2D or 3D space that signifies the underwater environment.

Example TCL Script for Basic Setup:

# Create a simulator instance

set ns [new Simulator]

# Define link parameters (bandwidth and delay)

set bw 1Mb          ;# Bandwidth for underwater communication

set delay 100ms     ;# High delay for underwater communication

# Create AUV nodes

set auv1 [$ns node]   ;# AUV 1

set auv2 [$ns node]   ;# AUV 2

set auv3 [$ns node]   ;# AUV 3

# Create links between AUVs (representing underwater communication links)

$ns duplex-link $auv1 $auv2 $bw $delay DropTail

$ns duplex-link $auv2 $auv3 $bw $delay DropTail

In this setup:

  • auv1, auv2, and auv3 are AUV nodes.
  • The communication links between them to replicate in underwater communication, that is usually has higher delays because of the nature of underwater acoustic waves.
  1. Define the Path for AUVs

The AUVs can follow predefined or enthusiastically created paths using the setdest command, which moves the AUV nodes to particular positions in a given time.

Example of Defining Movement for AUVs:

# Define the initial positions for the AUVs (in a 2D space)

$auv1 set X_ 0

$auv1 set Y_ 0

$auv2 set X_ 100

$auv2 set Y_ 0

$auv3 set X_ 200

$auv3 set Y_ 0

# Simulate the movement of AUVs along a planned path

$ns at 1.0 “$auv1 setdest 100 100 10”  ;# AUV 1 moves to position (100, 100) at 10 m/s

$ns at 2.0 “$auv2 setdest 200 200 8”   ;# AUV 2 moves to position (200, 200) at 8 m/s

$ns at 3.0 “$auv3 setdest 300 300 6”   ;# AUV 3 moves to position (300, 300) at 6 m/s

Here:

  • AUV1 moves to coordinates (100, 100) at a speed of 10 m/s.
  • AUV2 and AUV3 also move to their relevant destinations, mimicking the path planning process.
  1. Enable Communication between AUVs

For the AUVs to interact as they move, we can configure UDP or TCP agents and introduce interaction among the AUVs.

Example of Setting up Communication Between AUVs:

# Create UDP agent for AUV 1 (sender)

set udp_auv1 [new Agent/UDP]

$ns attach-agent $auv1 $udp_auv1

# Create CBR traffic generator to simulate constant packet flow

set cbr_auv1 [new Application/Traffic/CBR]

$cbr_auv1 set packet_size_ 1000

$cbr_auv1 set rate_ 512Kb

$cbr_auv1 attach-agent $udp_auv1

# Create a UDP sink at AUV 2 (receiver)

set udp_sink_auv2 [new Agent/Null]

$ns attach-agent $auv2 $udp_sink_auv2

# Connect AUV1 (sender) to AUV2 (receiver)

$ns connect $udp_auv1 $udp_sink_auv2

# Start and stop the communication

$ns at 2.0 “$cbr_auv1 start”

$ns at 10.0 “$cbr_auv1 stop”

This configuration permits AUV1 to send data to AUV2 using UDP and CBR (Constant Bit Rate) traffic to mimic underwater communication.

  1. Implement Path Planning Logic

To execute path planning, we can generate custom logic to enthusiastically adapt the AUV’s path based on network conditions or other factors such as energy consumption, obstacles, or connectivity.

Example: Dynamic Path Adjustment Based on AUV’s Position

We can observe an AUV’s position and adapts its path enthusiastically during the simulation.

# Define a procedure to dynamically adjust the AUV’s path

proc adjust_auv_path {} {

global ns auv1 auv2

# If AUV 1 reaches a certain position, change its path

if { [$auv1 set X_] >= 100 && [$auv1 set Y_] >= 100 } {

$ns at 6.0 “$auv1 setdest 300 300 5”   ;# AUV 1 changes its destination at 6.0 seconds

}

}

# Schedule the path adjustment

$ns at 5.0 “adjust_auv_path”

In this sample, AUV1 changes its destination if it reaches a particular position (100, 100). We can add more conditions to mimic path planning according to numerous factors.

  1. Enable Tracing and Monitor AUV Movements

To observe the movements of the AUVs and their communication, that can enable tracing in NS2.

Enable Trace Files:

# Enable tracing for the simulation

set tracefile [open “auv_path_planning_trace.tr” w]

$ns trace-all $tracefile

# Define a finish procedure to end the simulation and close the trace file

proc finish {} {

global ns tracefile

$ns flush-trace

close $tracefile

exit 0

}

# Set the simulation end time

$ns at 20.0 “finish”

The trace file will capture packet transmissions, AUV movements, and communication events, that permits measure the AUV network’s behaviour.

  1. Run the Simulation

Execute the simulation to monitor on how the AUVs move along their planned paths and how they interact with each other in the underwater environment.

# Run the simulation

$ns run

Example Complete TCL Script for AUV Path Planning Simulation

# Create a simulator instance

set ns [new Simulator]

# Define link parameters (bandwidth and delay for underwater communication)

set bw 1Mb

set delay 100ms

# Create AUV nodes

set auv1 [$ns node]

set auv2 [$ns node]

set auv3 [$ns node]

# Create links between AUVs (underwater communication links)

$ns duplex-link $auv1 $auv2 $bw $delay DropTail

$ns duplex-link $auv2 $auv3 $bw $delay DropTail

# Define the initial positions for the AUVs

$auv1 set X_ 0

$auv1 set Y_ 0

$auv2 set X_ 100

$auv2 set Y_ 0

$auv3 set X_ 200

$auv3 set Y_ 0

# Simulate the movement of AUVs along a planned path

$ns at 1.0 “$auv1 setdest 100 100 10”  ;# AUV 1 moves to (100, 100) at 10 m/s

$ns at 2.0 “$auv2 setdest 200 200 8”   ;# AUV 2 moves to (200, 200) at 8 m/s

$ns at 3.0 “$auv3 setdest 300 300 6”   ;# AUV 3 moves to (300, 300) at 6 m/s

# Create UDP agent for communication between AUV1 and AUV2

set udp_auv1 [new Agent/UDP]

$ns attach-agent $auv1 $udp_auv1

set cbr_auv1 [new Application/Traffic/CBR]

$cbr_auv1 set packet_size_ 1000

$cbr_auv1 set rate_ 512Kb

$cbr_auv1 attach-agent $udp_auv1

set udp_sink_auv2 [new Agent/Null]

$ns attach-agent $auv2 $udp_sink_auv2

# Connect AUV1 (sender) to AUV2 (receiver)

$ns connect $udp_auv1 $udp_sink_auv2

# Start and stop the communication

$ns at 2.0 “$cbr_auv1 start”

$ns at 10.0 “$cbr_auv1 stop”

# Define a procedure to dynamically adjust AUV 1’s path

proc adjust_auv_path {} {

global ns auv1

if { [$auv1 set X_] >= 100 && [$auv1 set Y_] >= 100 } {

$ns at 6.0 “$auv1 setdest 300 300 5”   ;# AUV 1 changes its destination

}

}

# Schedule the path adjustment

$ns at 5.0 “adjust_auv_path”

# Enable tracing

set tracefile [open “auv_path_planning_trace.tr” w]

$ns trace-all $tracefile

# End simulation

$ns at 20.0 “finish”

proc finish {} {

global ns tracefile

$ns flush-trace

close $tracefile

exit 0

}

# Run the simulation

$ns run

In the presented manual, we demonstrate the comprehensive procedures to implement and execute the Network Path Planning for Autonomous Underwater Vehicles that has key concepts, implementation procedures explanation and sample snippets were given to execute in ns2 tool. Additional specific details regarding the Network Path Planning for Autonomous Underwater Vehicles will be provided. To achieve great results, you can contact the ns2project.com team for the best implementation.