To simulate the Wireless Topology projects using NS2, encompasses to configure a wireless communication environment in which nodes are communicate through a wireless medium. In the wireless networks, the communication is normally according to the propagation of radio waves, and the network simulator NS2 supports numerous wireless models, like mobile ad-hoc networks (MANETs), sensor networks, and Wi-Fi networks. The below guide have the necessary details of Wireless Topology’s simulation in NS2:
Steps to Simulate Wireless Topology projects in NS2
Step 1: Understand Wireless Topology
In a Wireless Topology:
- Nodes are communicated wirelessly, including no predefined infrastructure like routers or switches.
- Nodes can be inactive or mobile, also their communication depends on the wireless channels, which usually utilizing the radio frequency propagation models.
- Wireless communication can be peer-to-peer, multi-hop (through intermediate nodes), or via access points that based on the situation.
Step 2: Design the Network
We will replicate the simple Wireless Topology in which:
- Nodes are arbitrarily located within a 2D space.
- Communication happens wirelessly among the nodes.
- A propagation model is utilized to replicate the radio wave transmission.
- A routing protocol like AODV or DSDV manages the packet forwarding within multi-hop situations.
Step 3: Create an NS2 TCL Script for Simulating Wireless Topology
The following is an NS2 TCL script, which replicates a Wireless Topology with arbitrarily located wireless nodes are communicating through a wireless channel.
Example: Wireless Topology Simulation in NS2
# Create a new NS2 simulator object
set ns [new Simulator]
# Define the parameters for the wireless topology
set opt(chan) Channel/WirelessChannel ;# Channel type
set opt(prop) Propagation/TwoRayGround ;# Propagation model
set opt(netif) Phy/WirelessPhy ;# Physical layer model
set opt(mac) Mac/802_11 ;# MAC layer model (Wi-Fi)
set opt(ifq) Queue/DropTail/PriQueue ;# Interface queue type
set opt(ll) LL ;# Link layer type
set opt(ant) Antenna/OmniAntenna ;# Antenna type
set opt(x) 500 ;# X dimension of the grid
set opt(y) 500 ;# Y dimension of the grid
set opt(adhocRouting) AODV ;# Ad-hoc routing protocol
# Create a topology object
set topo [new Topography]
$topo load_flatgrid $opt(x) $opt(y)
# General Operations Director (GOD) to keep track of nodes
create-god 10
# Configure node properties
$ns node-config -adhocRouting $opt(adhocRouting) \
-llType $opt(ll) \
-macType $opt(mac) \
-ifqType $opt(ifq) \
-ifqLen 50 \
-antType $opt(ant) \
-propType $opt(prop) \
-phyType $opt(netif) \
-channelType $opt(chan) \
-topoInstance $topo \
-agentTrace ON \
-routerTrace ON \
-macTrace ON \
-movementTrace ON
# Create wireless nodes
set num_nodes 10
set nodes {}
for {set i 0} {$i < $num_nodes} {incr i} {
set node [$ns node]
lappend nodes $node
}
# Randomly place nodes within the defined topology area
for {set i 0} {$i < $num_nodes} {incr i} {
set x_pos [expr rand() * $opt(x)]
set y_pos [expr rand() * $opt(y)]
[lindex $nodes $i] set X_ $x_pos
[lindex $nodes $i] set Y_ $y_pos
[lindex $nodes $i] set Z_ 0.0
}
# Attach UDP agents to two of the nodes for communication
set udp1 [new Agent/UDP]
set udp2 [new Agent/UDP]
$ns attach-agent [lindex $nodes 0] $udp1
$ns attach-agent [lindex $nodes 9] $udp2
# Attach Null agents to act as sinks at the opposite end devices
set null1 [new Agent/Null]
set null2 [new Agent/Null]
$ns attach-agent [lindex $nodes 9] $null1
$ns attach-agent [lindex $nodes 0] $null2
# Connect the UDP agents to their respective sinks
$ns connect $udp1 $null1
$ns connect $udp2 $null2
# Create CBR traffic from node 0 to node 9 and vice versa
set cbr1 [new Application/Traffic/CBR]
$cbr1 set packetSize_ 512
$cbr1 set interval_ 0.1
$cbr1 attach-agent $udp1
set cbr2 [new Application/Traffic/CBR]
$cbr2 set packetSize_ 512
$cbr2 set interval_ 0.1
$cbr2 attach-agent $udp2
# Start the traffic flows
$ns at 1.0 “$cbr1 start”
$ns at 1.5 “$cbr2 start”
# Create trace and nam files for recording the simulation events
set tracefile [open “wireless_topology.tr” w]
$ns trace-all $tracefile
set namfile [open “wireless_topology.nam” w]
$ns namtrace-all-wireless $namfile $opt(x) $opt(y)
# Define the finish procedure to close files and start NAM
proc finish {} {
global ns tracefile namfile
$ns flush-trace
close $tracefile
close $namfile
exec nam wireless_topology.nam &
exit 0
}
# Finish the simulation after 10 seconds
$ns at 10.0 “finish”
# Run the simulation
$ns run
Step 4: Explanation of the Script
- Wireless Channel Setup:
- The wireless channel is placed to Channel/WirelessChannel, including the TwoRayGround propagation model, 802.11 MAC layer, and Omnidirectional Antenna to replicate the wireless communication.
- Node Configuration:
- Ten wireless nodes are made and arbitrarily located within a 500×500 area.
- The AODV (Ad-hoc On-Demand Distance Vector) routing protocol is utilized to manage the multi-hop routing that permitting the packets to be sent by intermediate nodes if direct communication is not feasible.
- Traffic Setup:
- UDP agents are connected to the node 0 in addition node 9.
- CBR (Constant Bit Rate) traffic is made amongst these nodes that replicating a continuous flow of data packets among them.
- Tracing and Visualization:
- A trace file (wireless_topology.tr) is created to record every network events, like packet transmissions, receptions, and drops.
- For envisioning the wireless topology and the communication among the nodes, NAM file (wireless_topology.nam) is made.
Step 5: Run the Simulation
- We need to save the script as wireless_topology.tcl.
- Execute the script in NS2:
ns wireless_topology.tcl
It will create two files:
- wireless_topology.tr: A trace files, which records the packet-level information.
- wireless_topology.nam: A NAM file for envisioning the network in NAM.
Step 6: Visualize the Simulation Using NAM
To envision the Wireless Topology in NAM:
nam wireless_topology.nam
In NAM, we will observe:
- The arbitrarily located the wireless nodes.
- Packet transmissions among the nodes as the CBR traffic flows since node 0 to node 9 via intermediate nodes.
Step 7: Analyze the Trace File
The trace file (wireless_topology.tr) records every network events, like:
- Packet transmissions and receptions among the nodes.
- Packet drops or delays are triggered by distance or wireless channel interference.
We can be utilized the tools such as AWK, Python, or custom scripts to examine the trace file and extract crucial performance parameters like:
- Packet delivery ratio (PDR).
- End-to-end delay amongst nodes.
- Network throughput and performance under diverse situation.
Step 8: Enhance the Simulation
There are few ways to prolong or improve the simulation:
- Add Node Mobility: Launch the mobility by creating the nodes are move dynamically in the simulation with the support of mobility models (e.g., Random Waypoint Model).
- Simulate Link Failures: Launch link failures by reason of the signal interference or node mobility to monitor how the routing protocol manages the disconnections.
- Dynamic Traffic: To replicate the diverse kinds of traffic such as FTP, VoIP to design real-world wireless networks.
- Energy Models: Insert an energy models to mimic the power consumption within wireless sensor networks (WSNs).
- Larger Topologies: Maximize the amount of nodes and grid size to replicate the bigger and more complex wireless networks.
Through this manual, we had given the step-by-step approach on how to execute and analyse the Wireless Topology projects which is set up a wireless communication environment through a wireless medium. We were also offered additional data with snippet codes for your references.
Our team can help you analyze the performance of your project. We work on many wireless models, such as mobile ad-hoc networks (MANETs), sensor networks, and Wi-Fi networks. If you want to simulate Wireless Topology Projects using the NS2 tool, phdprime.com is here to provide you with the best solutions and guidance. We can also help you come up with great thesis ideas and topics that fit your interests.
