How to Start IEEE 802.11 WiFi Projects Using NS2

To create an IEEE 802.11 (Wi-Fi) projects using Network Simulator 2 (NS2), we will require the replication of Wi-Fi (802.11) wireless communication protocols and traffic models and estimate the performance of Wi-Fi networks in different scenarios. NS2 has built-in help for IEEE 802.11 that can be used to replicate the wireless local area networks (WLANs). Here’s a step-by-step guide on how to begin:

Steps to Start IEEE 802.11 (Wi-Fi) Projects Using NS2

Step 1: Install NS2

Assure which have NS2 installed on the system. If NS2 is not installed, follow these procedures:

  • For Linux (Ubuntu):

sudo apt-get install ns2

  • For macOS or Windows, we can observe the installation procedures from the official NS2 website.

After installed, validate if NS2 is functioning through typing ns in the terminal. This should open the NS2 command prompt.

Step 2: Understand IEEE 802.11 Protocol

The IEEE 802.11 standard describes the specifications for Wi-Fi (wireless LAN). It includes:

  • MAC Layer: Maintain the medium access control, state on how devices distribute the wireless channel.
  • PHY Layer: Describes the physical medium for communication, like as the frequency bands used for transmission.
  • Types of 802.11: Various versions of IEEE 802.11 for sample 802.11a, 802.11b, and 802.11g, 802.11n works in various frequency bands and help for several data rates. NS2 primarily supports the 802.11b version for replication.

In NS2, we will design the MAC (Medium Access Control) layer and the PHY (Physical) layer of Wi-Fi devices it replicate the communication among wireless devices such as laptops, smartphones, and routers.

Step 3: Network Setup and Topology Design

Model the topology for Wi-Fi network. Study the following module:

  1. Access Points (APs): Devices which offers the wireless connectivity to clients.
  2. Wireless Clients: Devices that connect to the Wi-Fi network for sample laptops, smartphones.
  3. Wireless Links: Connections among the access point and the clients.
  4. Traffic Models: We require choosing the kinds of congestion such as CBR for constant bit rate, FTP for file transfer, Telnet, etc.

The basic Wi-Fi network contains for a few wireless clients communicating by an access point.

Step 4: Write an NS2 Script for 802.11 Simulation

Here’s a simple NS2 script which configure basic IEEE 802.11 replication through two nodes communicating over a wireless link (using 802.11b):

# Create simulator

set ns [new Simulator]

# Create nodes (1 Access Point and 2 Clients)

set ap [$ns node]

set client1 [$ns node]

set client2 [$ns node]

# Set up wireless channels (using 802.11b for Wi-Fi)

$ns node-config -channel $channel -ifqType Queue/DropTail -ifqLen 50 -ant 1 -propagationPropagation/TwoRayGround -phyType Phy/WirelessPhy -macType Mac/802_11 -channelBandwidth 2Mb -energyModel EnergyModel

# Create a wireless link between the access point and the clients

$ns duplex-link $client1 $ap 10Mb 10ms

$ns duplex-link $client2 $ap 10Mb 10ms

# Create TCP and UDP agents

set tcp1 [new Agent/TCP]

$ns attach-agent $client1 $tcp1

set sink1 [new Agent/TCPSink]

$ns attach-agent $ap $sink1

$ns connect $tcp1 $sink1

set tcp2 [new Agent/TCP]

$ns attach-agent $client2 $tcp2

set sink2 [new Agent/TCPSink]

$ns attach-agent $ap $sink2

$ns connect $tcp2 $sink2

# Set up FTP applications to simulate traffic

set ftp1 [new Application/FTP]

$ftp1 attach-agent $tcp1

set ftp2 [new Application/FTP]

$ftp2 attach-agent $tcp2

# Set simulation time and run

$ns run

Explanation of the Script:

  • Node Creation: We build a three nodes — one access point (ap) and two clients (client1 and client2).
  • Wireless Channel: The wireless channel is set-up through basic parameters such as bandwidth, delay, and PHY layer. Here, Phy/WirelessPhy and Mac/802_11 represent the wireless physical and MAC layers.
  • Links: We describe the wireless connection among the clients and the access point, requiring bandwidth and delay.
  • TCP Traffic: TCP agents are attached the clients and assign the point of replication traffic. We setting the FTP applications and create the data transfer.
  • Simulation: The script process for the specified duration to replicate the interaction among the nodes.

Step 5: Run the Simulation

We process for the replication, store the script as 80211_simulation.tcl and run the following command:

ns 80211_simulation.tcl

Step 6: Analyze the Results

Next the replication finishes, NS2 creates a trace file it includes the specific data about the packets transmitted, received, and other action in the replication. We can analyze this trace file using tools like Xgraph or AWK scripts we process the data and visualize main metrics such as:

  • Throughput: Evaluate on how much data is transmitted over the network.
  • Delay: Measure the end-to-end delay from the sender to the receiver.
  • Packet Loss: Estimate on how many packets were lost during transmission.
  • Collision: Follow on the number of collisions which occur due to wireless medium contention.

For graphical analysis:

xgraph tracefile.tr

Step 7: Experiment and Extend the Simulation

After you’ve setting a simple replication and it can research by different parameters:

  1. Add More Clients: Increase the number of clients and estimate the network’s performance as the load rises.
  2. Use Different Traffic Types: Replicate the various kinds of congestion like FTP, HTTP, and voice for sample VoIP to follow on how the network handles them.
  3. Adjust Transmission Range: Adjust the transmission power and range the replication of different network coverage and interference.
  4. Change Routing Protocols: Designed for further advanced Wi-Fi networks, replicate routing protocols such as AODV or DSR.
  5. Simulate Mobility: Use the Mobility design in NS2 and replicate the client movement in the network.

Example of Adding Mobility:

To simulate client movement, you can add a mobility model:

# Set client mobility (e.g., linear movement)

$ns node-config -mobilenode $client1

$client1 random-motion 1

Step 8: Debugging and Troubleshooting

  • Check Trace Files: If the replication is not operates as expected, check the trace files for errors, like as packet loss, collisions, or other network issues.
  • Use Debugging Mode: We can improve the debugging information to the script to output status messages during the replication:

puts “Simulation Running…”

Step 9: Documentation and Reporting

Prepare a report with:

  • Simulation Setup: State the topology, nodes, and congestion models used.
  • Results and Analysis: It Contain the graphs and analysis of throughput, delay, packet loss, etc.
  • Conclusions: Summarize the performance metrices and visions form the replication.

The above project concept explores numerous contexts of IEEE 802.11 Wi-Fi projects performance and the detailed installation procedures to simulate the IEEE 802.11 Wi-Fi projects in ns2 tool. If you’d like more details on any specific project, feel free to ask!