How to Implement Route Access Protocol in NS2

To implement a specific Route Access Protocol (RAP) in NS2 has commonly included generating a custom execution if the protocol is already supported. NS2 primarily helps to standard routing protocols like an AODV, DSR, and DSDV. If RAP is not natively supported in NS2 that need to describe the protocol’s behaviour using Tcl scripts or expand the NS2 with custom C++ code.

The given below are the brief structured procedures to implement the simple custom Route Access Protocol in NS2:

Step-by-Step Implementation:

Step 1: Understand the Route Access Protocol

Before executing RAP in NS2, we need a clear consideration of how this protocol operates and it involves on how routes are introduced, maintained, and any particular parameters or algorithms used.

Step 2: Set Up NS2

Make sure NS2 is installed on the system.

Step 3: Create a Basic Simulation Script

To mimic a custom routing protocol in NS2, we typically need to:

Configure the simulation environment
Describe the nodes and their behaviour
Execute the custom routing logic

Example: Creating a Custom RAP in NS2

Create a New Tcl Script: Open a text editor and generate a new file, for instance, custom_rap_example.tcl.
Set Up the Simulation Environment: Describe the simulator, network topology, and basic parameters.

# Create a simulator object

set ns [new Simulator]

# Define options for the simulation

set val(chan) Channel/WirelessChannel ;# Channel type

set val(prop) Propagation/TwoRayGround ;# Propagation model

set val(netif) Phy/WirelessPhy ;# Network interface type

set val(mac) Mac/802_11 ;# MAC type

set val(ifq) Queue/DropTail/PriQueue ;# Interface Queue type

set val(ll) LL ;# Link layer type

set val(ant) Antenna/OmniAntenna ;# Antenna type

set val(ifqlen) 50 ;# Max packet in ifq

set val(nn) 10 ;# Number of nodes

set val(x) 500 ;# X dimension of topography

set val(y) 500 ;# Y dimension of topography

set val(stop) 100.0 ;# Simulation time

# Initialize the topology object

set topo [new Topography]

$topo load_flatgrid $val(x) $val(y)

# Create the God object

create-god $val(nn)

# Configure the nodes

$ns node-config -llType $val(ll) \

-macType $val(mac) \

-ifqType $val(ifq) \

-ifqLen $val(ifqlen) \

-antType $val(ant) \

-propType $val(prop) \

-phyType $val(netif) \

-channelType $val(chan) \

-topoInstance $topo \

-agentTrace ON \

-routerTrace ON \

-macTrace ON \

-movementTrace ON

# Create nodes

for {set i 0} {$i < $val(nn)} {incr i} {

set node_($i) [$ns node]

}

# Define node positions

$node_(0) set X_ 100.0

$node_(0) set Y_ 200.0

$node_(1) set X_ 200.0

$node_(1) set Y_ 300.0

$node_(2) set X_ 300.0

$node_(2) set Y_ 400.0

# Additional nodes…

# Implement custom RAP logic

# You may need to define functions or procedures that simulate the routing behavior

Step 4: Implement the Custom Routing Logic

We state on how the custom RAP works. Meanwhile NS2 primarily supports Tcl scripting; we can write procedures that emulate the behaviour of RAP. Though, if RAP has complex mechanisms, we essential to adjust the NS2 C++ source code.

Example Custom Routing Logic in Tcl:

proc route-discovery {src dst} {

global ns node_

# Logic to discover a route from src to dst

# Example: broadcasting a route request, waiting for a reply, etc.

}

proc route-maintenance {src dst} {

global ns node_

# Logic to maintain an existing route

# Example: checking the route’s validity, repairing broken routes, etc.

}

# Example of using the custom route discovery procedure

$ns at 1.0 “route-discovery $node_(0) $node_(2)”

Step 5: Set Up Traffic Sources

Describe the communication among the nodes.

# Setup a UDP agent and attach it to the first node

set udp [new Agent/UDP]

$ns attach-agent $node_(0) $udp

# Setup a CBR application to generate traffic

set cbr [new Application/Traffic/CBR]

$cbr attach-agent $udp

$cbr set packetSize_ 512

$cbr set interval_ 0.1

$cbr start

# Setup a Null agent (sink) on another node

set null [new Agent/Null]

$ns attach-agent $node_(2) $null

# Connect the agents

$ns connect $udp $null

Step 6: Define Simulation End

# Define simulation end time

$ns at $val(stop) “stop”

$ns at $val(stop) “$ns nam-end-wireless $val(stop)”

$ns at $val(stop) “exit 0”

proc stop {} {

global ns tracefile namfile

$ns flush-trace

close $tracefile

close $namfile

}

# Run the simulation

$ns run

Step 7: Run the Simulation

Save the Tcl script (custom_rap_example.tcl).
Open a terminal and navigate to the directory in which we saved the Tcl script.
Execute the simulation using the following command:

ns custom_rap_example.tcl

This command will create the trace files and optionally a network animation file (if enabled in script).

Step 8: Analyse the Results

Use trace files and the network animator (NAM) to evaluate the performance of the custom RAP that concentrates on parameters like route discovery time, packet delivery ratio, end-to-end delay, and network overhead.

Additional Considerations

Protocol Complexity: If the protocol is complex, deliberately expanding NS2’s C++ codebases to add a new routing agent.
Performance Metrics: Assess the performance of the custom RAP in numerous network scenarios.
Scalability: Validate on how the custom RAP scales with an increasing number of nodes and network size.

According to this procedure we have seen and aggregated the essential information regarding the example based on Route Access Protocol that includes the simulation process in the ns2 tool. We will also offer more information about the Route Access Protocol. We work on all protocols and give you best simulation assistance.