To simulate Wireless Communication projects in NS2 has includes to set up wireless nodes, mobility models, wireless communication protocols, and traffic models to replicate realistic wireless communication networks such as Mobile Ad-hoc Networks (MANETs), Wireless Sensor Networks (WSNs), and Cellular Networks.
Here’s a detailed guide on how to simulate Wireless Communication Projects using NS2:
Steps for Simulating Wireless Communication Projects in NS2
- Install NS2: Make sure that NS2 is installed on system. If you’re using Linux, we can install NS2 using the following command:
sudo apt-get install ns2
Validate the installation by typing:
ns -version
- Understand the NS2 Wireless Components: In NS2, wireless communication is supported through components like:
- MobileNode: Wireless nodes that interact without wired connections.
- WirelessChannel: Shared communication medium for all wireless nodes.
- Routing Protocols: Ad-hoc routing protocols such as AODV (Ad-hoc On-demand Distance Vector), DSDV (Destination-Sequenced Distance-Vector), and DSR (Dynamic Source Routing).
- Traffic Models: Describes the traffic pattern among nodes, like CBR (Constant Bit Rate) over UDP, FTP over TCP, and more.
- Create a Wireless Communication Scenario Using Tcl Script: Let’s replicate a Wireless Ad-hoc Network with multiple mobile nodes using AODV routing protocol and UDP traffic.
Example Tcl Script for a Wireless Communication Simulation
# Create a new simulator object
set ns [new Simulator]
# Open trace and NAM files for output
set tracefile [open wireless_comm_out.tr w]
$ns trace-all $tracefile
set namfile [open wireless_comm_out.nam w]
$ns namtrace-all-wireless $namfile 500 500
# Define the wireless channel
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 (Wi-Fi)
set val(ifq) Queue/DropTail/PriQueue ;# Interface queue type
set val(ll) LL ;# Link Layer
set val(ant) Antenna/OmniAntenna ;# Antenna model
set val(ifqlen) 50 ;# Interface queue length
set val(x) 500 ;# X dimension of the topology
set val(y) 500 ;# Y dimension of the topology
set val(nn) 5 ;# Number of nodes
set val(rp) AODV ;# Routing protocol (AODV)
# Define the topology object
set topo [new Topography]
$topo load_flatgrid $val(x) $val(y)
# Configure node settings for wireless communication
$ns node-config -adhocRouting $val(rp) \
-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 $topo \
-agentTrace ON \
-routerTrace ON \
-macTrace ON
# Create mobile nodes
for {set i 0} {$i < $val(nn)} {incr i} {
set node_($i) [$ns node]
$node_($i) random-motion 0 ;# Disable random motion initially
}
# Set node initial positions
$node_(0) set X_ 50.0
$node_(0) set Y_ 50.0
$node_(0) set Z_ 0.0
$node_(1) set X_ 150.0
$node_(1) set Y_ 150.0
$node_(1) set Z_ 0.0
$node_(2) set X_ 250.0
$node_(2) set Y_ 250.0
$node_(2) set Z_ 0.0
$node_(3) set X_ 350.0
$node_(3) set Y_ 350.0
$node_(3) set Z_ 0.0
$node_(4) set X_ 450.0
$node_(4) set Y_ 450.0
$node_(4) set Z_ 0.0
# Define UDP traffic: node 0 to node 4
set udp [new Agent/UDP]
$ns attach-agent $node_(0) $udp
set null [new Agent/Null]
$ns attach-agent $node_(4) $null
$ns connect $udp $null
# Create CBR traffic over UDP
set cbr [new Application/Traffic/CBR]
$cbr set packetSize_ 512
$cbr set interval_ 0.05 ;# 50ms interval for CBR traffic
$cbr attach-agent $udp
# Schedule traffic start and stop times
$ns at 1.0 “$cbr start”
$ns at 4.5 “$cbr stop”
# Schedule mobility: node 0 moves to a new position
$ns at 0.5 “$node_(0) setdest 450.0 450.0 10.0”
# Define simulation end
$ns at 6.0 “finish”
# Define finish procedure to close trace files and run NAM visualization
proc finish {} {
global ns tracefile namfile
$ns flush-trace
close $tracefile
close $namfile
exec nam wireless_comm_out.nam &
exit 0
}
# Run the simulation
$ns run
Explanation of the Tcl Script:
- Simulator Object:
- The line set ns [new Simulator] generates the simulator object that regulate the entire simulation.
- Trace and NAM Files:
- Trace file (wireless_comm_out.tr) logs all events in the simulation (packet transmission, reception, etc.).
- NAM file (wireless_comm_out.nam) is utilzed for envision the simulation in Network Animator (NAM).
- Wireless Configuration:
- Wireless communication is set up using Channel/WirelessChannel and 802.11 MAC for Wi-Fi communication.
- OmniAntenna is utilized for all-directional wireless communication, and the propagation model is set to TwoRayGround.
- Routing protocol is AODV (Ad-hoc On-demand Distance Vector).
- Node Creation and Mobility:
- Five wireless nodes (node_(0) to node_(4)) are generated and positioned in a 500×500 grid.
- Node 0 moves to a new destination (450, 450) at a speed of 10 units per second using the setdest command, simulating mobility.
- Traffic Model:
- A UDP agent is attached to node_(0) and a Null agent (sink) is attached to node_(4).
- CBR (Constant Bit Rate) traffic is created among node 0 and node 4, with packets of size 512 bytes sent every 50ms.
- Simulation Events:
- Traffic initiates at 1 second and terminates at 4.5 seconds.
- The simulation ends at 6 seconds.
- Running the Simulation:
Save the script as wireless_comm_simulation.tcl and execute it in NS2:
ns wireless_comm_simulation.tcl
After the simulation completes, we can envision the network in NAM by running:
nam wireless_comm_out.nam
- Analysing the Results:
- Trace File Analysis: The trace file (wireless_comm_out.tr) logs packet transmission, reception, and routing decisions. We can measure this file to extract parameters such as throughput, end-to-end delay, and packet delivery ratio using AWK scripts or other evaluation tools.
Example AWK script to calculate Throughput:
BEGIN {
packet_count = 0;
start_time = 0;
end_time = 0;
}
{
if ($1 == “r” && $4 == “AGT”) {
packet_count++;
if (start_time == 0) {
start_time = $2;
}
end_time = $2;
}
}
END {
duration = end_time – start_time;
throughput = (packet_count * 512 * 8) / (duration * 1000); # kbps
printf(“Throughput: %.2f kbps\n”, throughput);
}
Extending the Simulation:
- Add More Nodes and Traffic Patterns:
- We can add more nodes, traffic flows such as FTP over TCP, and routing protocols like DSDV, DSR to generate more complex wireless communication environment.
- Experiment with Different Mobility Models:
- Utilize Random Waypoint, Random Walk, or Gauss-Markov mobility models to replicate node movement in a realistic environment.
- Simulate Wireless Sensor Networks (WSN):
- We can adjust the script to replicate Wireless Sensor Networks by establishing sensor nodes, base stations, and proper data traffic models.
- Simulate Cellular Networks:
- We can simulate cellular networks with base stations and mobile nodes using cellular protocols.
- Performance Evaluation:
- Measure parameters like packet delivery ratio, average delay, throughput, and routing overhead by run the trace files using scripts or tools such as TraceGraph.
From this manual, you can able to explore the numerous contexts and techniques that will enable to simulate the wireless communication using ns2 tool and it has detailed simulation procedures, extension of this concepts and performance analysis and finally it provides the sample codes. If you did like to know more details regarding this process we will offered it.
We specialize in Mobile Ad-hoc Networks (MANETs), Wireless Sensor Networks (WSNs), and Cellular Networks related to your projects. Share the details of your Wireless Communication Projects with us, and we will provide tailored simulation support to meet your needs.
