How to Start Wireless Sensor Network Projects Using NS2

To start a Wireless Sensor Network (WSN) project in NS2 (Network Simulator 2) which needs to replicate the wireless sensor nodes, its interaction, and routing protocols are modeled for WSNs. WSNs normally have large volume of sensor nodes, which observe the physical situations such as temperature, humidity, and motion, and interact its readings through wireless communication to a base station or sink node.

Below is a structured technique to getting started with Wireless Sensor Network (WSN) simulations using NS2:

Steps to Start Wireless Sensor Network Projects in NS2

  1. Install NS2

Make sure that we have NS2 is installed on the system before starting the projects. Adhere to the installation instructions as defined in the previous answers.

Go to NS2 official website or use the commands to install on a Linux/Ubuntu system for downloading the new version of NS2.

  1. Set Up Wireless Sensor Network Topology

In a common WSN, nodes are distributed around an area, and they wirelessly interact for transmitting the information to a sink node. It needs to describe the sensor nodes, communication channels, mobility, and application-specific metrics like data collection intervals.

Example: Basic Wireless Sensor Network with Two Nodes

This instance illustrates basic network scenario including two nodes and simple UDP communication.

# Create simulator instance

set ns [new Simulator]

# Create wireless sensor nodes

set node1 [$ns node]

set node2 [$ns node]

set node3 [$ns node]

# Set up wireless communication links

$ns wireless-link $node1 $node2 1Mb 10ms

$ns wireless-link $node2 $node3 1Mb 10ms

# Set up UDP communication between nodes (for example, sensor data transmission)

set udp [new Agent/UDP]

$ns attach-agent $node1 $udp

set sink [new Agent/Null]

$ns attach-agent $node3 $sink

$ns connect $udp $sink

# Start the UDP data transmission at time 1.0s

$ns at 1.0 “$udp send”

$ns at 5.0 “finish”

# Run the simulation

$ns run

# Procedure to finish the simulation

proc finish {} {

global ns

$ns flush-trace

exit 0

}

Explanation:

  • Wireless Links: Make wireless links among the nodes including bandwidth and delay settings (1 Mbps, 10ms).
  • UDP Traffic: The UDP agent is utilised for replicating the interaction among the nodes such as node1 and node3 to transmit sensor information.
  • Simulation Control: Traffic begins at 1 second, and the simulation ends at 5 seconds.
  1. Add Mobility for Sensor Nodes

For a more realistic simulation, we can specifically utilise for mobile sensor networks, we will need to insert mobility models. Sensor nodes are normally immobile, however in specific applications, mobility models probably essential in WSNs.

Example: Random Waypoint Mobility Model

In this case, the sensor nodes will arbitrarily transfer in a defined area.

# Create simulator instance

set ns [new Simulator]

# Create wireless sensor nodes

set node1 [$ns node]

set node2 [$ns node]

# Set wireless link parameters

$ns wireless-link $node1 $node2 1Mb 10ms

# Set mobility model

$node1 set X_ 0.0

$node1 set Y_ 0.0

$node2 set X_ 100.0

$node2 set Y_ 100.0

# Enable random waypoint mobility for the nodes

$ns at 0.0 “$node1 random-motion”

$ns at 0.0 “$node2 random-motion”

# Set up UDP traffic between nodes

set udp [new Agent/UDP]

$ns attach-agent $node1 $udp

set sink [new Agent/Null]

$ns attach-agent $node2 $sink

$ns connect $udp $sink

# Start traffic at time 1.0s

$ns at 1.0 “$udp send”

$ns at 5.0 “finish”

# Run the simulation

$ns run

proc finish {} {

global ns

$ns flush-trace

exit 0

}

Explanation:

  • Mobility Model: The nodes random places and the random-motion technique are creates them to arbitrarily transfer within the area.
  1. Implement Routing Protocols for WSN

WSNs frequently utilise the routing protocols which is particularly modeled for managing the wireless sensor networks’ unique challenges like low power consumption, scalability, and reliability. NS2 environment offers diverse routing protocols such as AODV, DSR, and LEACH (Low-Energy Adaptive Clustering Hierarchy) that is a protocol especially used for WSNs.

Example: Implementing AODV Routing Protocol for WSN

# Create simulator instance

set ns [new Simulator]

# Create nodes

set node1 [$ns node]

set node2 [$ns node]

set node3 [$ns node]

# Set the routing protocol to AODV for WSNs

$node1 set protocol AODV

$node2 set protocol AODV

$node3 set protocol AODV

# Create wireless links between nodes

$ns wireless-link $node1 $node2 1Mb 10ms

$ns wireless-link $node2 $node3 1Mb 10ms

# Set up UDP traffic for data transmission

set udp [new Agent/UDP]

$ns attach-agent $node1 $udp

set sink [new Agent/Null]

$ns attach-agent $node3 $sink

$ns connect $udp $sink

# Start sending data at time 1.0s

$ns at 1.0 “$udp send”

$ns at 5.0 “finish”

# Run the simulation

$ns run

proc finish {} {

global ns

$ns flush-trace

exit 0

}

Explanation:

  • Routing Protocol (AODV): AODV is typically utilised within WSNs, and by configuring routing protocol AODV, the nodes will be applied this protocol for routing information to the destination node.
  1. Simulate WSN Applications (Data Collection, Aggregation)

Data collection and data aggregation method is crucial features of WSNs. NS2 permits for replicating the applications like temperature or humidity sensing.

Example: Data Aggregation in WSN

Here, we can replicate a basic data aggregation scenario in which nodes within the network sense a value (e.g., temperature) and transmit it to a sink node. The aggregation will execute at the sink node.

# Create simulator instance

set ns [new Simulator]

# Create sensor nodes and set positions

set node1 [$ns node]

set node2 [$ns node]

set node3 [$ns node]

# Set wireless links

$ns wireless-link $node1 $node2 1Mb 10ms

$ns wireless-link $node2 $node3 1Mb 10ms

# Set up data aggregation application (temperature sensing)

set app1 [new Application/Traffic/CBR]

$app1 attach-agent $node1

$app1 set packetSize_ 512

$app1 set rate_ 1000

$app1 set dstNode $node3

# Start data sensing application at time 1.0s

$ns at 1.0 “$app1 start”

$ns at 5.0 “finish”

# Run the simulation

$ns run

proc finish {} {

global ns

$ns flush-trace

exit 0

}

Explanation:

  • Data Aggregation: The sensor nodes transmit the data such as temperature readings, to the sink node. In real-world WSNs, the sink node might combine this information for detailed analysis.
  1. Visualize the Simulation Using NAM

When the simulation is accomplished then we need to envision the outcomes with the support of NAM (Network Animator). NAM is a graphical tool for envisioning how nodes in a network transfer, communicate, and send data.

To generate and visualize the NAM file:

  1. Integrate it to the end of the script to make a .nam file:

set namfile output.nam

$ns namtrace-all $namfile

  1. Execute the simulation:

ns wireless_sensor_network.tcl

  1. Go to the NAM file with the following command:

nam output.nam

  1. Analyze the Results

When simulation is executed then we need to examine the outcomes by searching the trace file (.tr) which is generated by NS2. This file has in-depth data regarding packet transmission, node movements, and event times.

Analyse the trace file to utilise AWK scripts for performance parameters like:

  • Energy consumption (if modeled)
  • Delay
  • Throughput
  • Packet loss

For instance, computing the throughput, we might utilise an AWK script for calculating the volume of packets which are transmitted and inherited over time.

  1. Extend Your Simulation

When we have configured the simple WSN simulation then we prolong it to more advanced scenarios:

  • Energy Models: We will need to replicate the power utilization for designing the battery-powered sensor nodes restrictions.
  • Fault Tolerance: Launch network failures or mimic the effect of node failures.
  • Advanced Routing Protocols: Execute more advanced routing protocols like LEACH (Low-Energy Adaptive Clustering Hierarchy) or TEEN for power-efficient data collection.
  • Scalability: Mimic large-scale networks including hundreds or thousands of sensor nodes.

Conclusion

Starting a Wireless Sensor Network (WSN) project using NS2:

  1. Install NS2 and configure the environment.
  2. Create a network topology and make wireless sensor nodes.
  3. Integrate mobility to the sensor nodes as required.
  4. Execute the routing protocols which are customized to WSNs such as AODV, LEACH, or DSR.
  5. Replicate WSN applications like data collection and aggregation.
  6. Envision the simulation to utilise NAM and then examine the outcomes.
  7. Prolong simulation including energy models, fault tolerance, and other advanced aspects.

In this manual, we can make a various kinds of wireless sensor network simulations within NS2 tool applying provided simulation steps with sample snippets. Further insights will follow in another guide.