How to Implement Network VSN in NS2

To implement a Visual Sensor Network (VSN) in NS2 has includes to mimic a network of sensor nodes that capture, process, and interact visual data such as images or video. VSNs can be deliberated a subclass of wireless sensor networks (WSNs) in which the nodes are fitted out with visual sensing capabilities, that has commonly used the cameras, and transfer this data via the network. NS2 is mainly used for mimic the communication protocols, so the simulation will concentrate on the networking aspects of VSN, like data transmission, routing, and energy consumption.

In the given below are the procedures to implement the Visual Sensor Network (VSN) in NS2:

Step-by-Step Implementation:

  1. Set up the Network Environment

Initiate by describing the simulation environment in NS2, that contain to configuring nodes, the wireless channel, and the propagation model. In a VSN, the nodes denote cameras or visual sensors that capture and send data.

TCL Script:

# Create a simulator instance

set ns [new Simulator]

# Define network parameters (Wireless environment)

set val(chan) Channel/WirelessChannel         ;# Wireless channel

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

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

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

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

set val(ll) LL                                ;# Link layer type

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

set val(x) 1000                               ;# X dimension of topography

set val(y) 1000                               ;# Y dimension of topography

set val(rp) AODV                              ;# Routing protocol

# Create a topography object

create-god 10                                 ;# Number of nodes in the network

This configures the simple network metrics such as wireless communication, propagation model, MAC protocol, and antenna type.

  1. Create Visual Sensor Nodes

In a VSN, each node is a visual sensor, so describe these nodes as part of a wireless sensor network. In NS2, we can mimic these sensor nodes by describing nodes with wireless communication capabilities.

Example TCL Script to Create Nodes:

# Create nodes and set positions

for {set i 0} {$i < 10} {incr i} {

set node_($i) [$ns node]

}

# Define node positions (for static VSN, you can assign fixed positions)

$node_(0) set X_ 100

$node_(0) set Y_ 100

$node_(1) set X_ 200

$node_(1) set Y_ 150

# Add other nodes…

# Set energy model for sensor nodes (optional if simulating energy consumption)

for {set i 0} {$i < 10} {incr i} {

$node_($i) set energyModel_ EnergyModel

$node_($i) set initialEnergy_ 100.0 ;# Set initial energy for nodes

}

This generates the sensor nodes and assigns positions. These nodes are equipped with an energy model to mimic the limited power available in sensor nodes.

  1. Generate Visual Data Traffic

In VSN, visual sensors create a high volume of data compared to old sensor networks. We can design this by using UDP or TCP traffic to mimic the transmission of images or video streams. The traffic generator, like CBR (Constant Bit Rate), can denote the continuous visual data being routed by the sensors.

Example of Creating UDP Traffic for Visual Data:

# Create a UDP agent (source) for sending visual data from a sensor node

set udp [new Agent/UDP]

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

# Create a traffic generator (CBR) to simulate continuous visual data transmission

set cbr [new Application/Traffic/CBR]

$cbr set packet_size_ 1024 ;# Simulating large data packets for visual data

$cbr set rate_ 1Mb ;# 1 Mbps transmission rate

$cbr attach-agent $udp

# Create a UDP sink (receiver) on another node

set null [new Agent/Null]

$ns attach-agent $node_(1) $null

$ns connect $udp $null

# Start and stop the transmission of visual data

$ns at 1.0 “$cbr start”

$ns at 10.0 “$cbr stop”

Here, the CBR traffic generator mimics the continuous video streaming among the sensor nodes (node 0 transmits to node 1). The packet size and rate are set to implement the features of visual data.

  1. Implement Routing Protocol for VSN

To enable communication among the visual sensor nodes, we can use a routing protocol. In NS2, we can execute an AODV, DSR, or any other ad-hoc routing protocol. These protocols supports the sensor nodes discover routes to transfer the data to the base station or other sensor nodes.

Example of Using AODV Routing Protocol:

# Set up the routing protocol (AODV in this case)

set val(rp) AODV

# Attach the routing protocol to all nodes

for {set i 0} {$i < 10} {incr i} {

$node_($i) set ragent [$val(rp)]

}

This enables the sensor nodes to enthusiastically discover routes for conducting visual data to the destination nodes.

  1. Multihop Transmission

Meanwhile VSN nodes not all is in direct communication range, multihop transmission is vital. In this scenario, some sensor nodes will behave as relay nodes, forwarding the data to other nodes. NS2 will manage this spontaneously across the routing protocol that has chosen.

  1. Simulate Visual Data Aggregation (Optional)

In VSN, nodes might also perform data aggregation to minimize the amount of data transmitted. This can be mimicked by integrating multiple small packets into larger ones, or by adjusting the packet rate dynamically.

Example of Data Aggregation:

# Adjust the packet size to simulate data aggregation

$cbr set packet_size_ 2048 ;# Larger packet size to represent aggregated data

This increases the packet size, minimizing the number of transmissions needded for the same amount of data.

  1. Implement Data Processing and Forwarding (Optional)

In VSN, nodes process data before forwarding it. This can be modelled by adding delays or enthusiastically varying the data being sent. We can mimic this by establishing a custom agent in NS2 that adds processing time.

# Simulate data processing delay before forwarding

proc process_and_forward {src_node dst_node data} {

set delay 2.0 ;# Processing delay (in seconds)

$ns_ at [expr [now] + $delay] “$src_node forward $data to $dst_node”

}

This establishes latency in processing the data before forwarding it to the next node.

  1. Simulate Power Consumption (Optional)

Meanwhile VSN nodes are usually battery-powered, that mimic power consumption is essential. NS2 has a built-in energy design that tracks energy usage during communication.

Example of Simulating Power Consumption:

# Set initial energy and track energy consumption for each node

for {set i 0} {$i < 10} {incr i} {

$node_($i) set energyModel_ EnergyModel

$node_($i) set initialEnergy_ 100.0 ;# Set initial energy for each node

}

  1. Monitor and Trace the Simulation

Allow tracing to observe the performance of the VSN. We can track parameters such as packet delivery ratio (PDR), end-to-end delay, throughput, and energy consumption.

Enable Trace Files for Analysis:

# Enable tracing for the simulation

set tracefile [open “vsn_trace.tr” w]

$ns trace-all $tracefile

The trace file will store all events like packet transmission, reception, and energy consumption for analysis after the simulation.

  1. Run the Simulation

Finally, we can execute the simulation by specifying when the simulation should terminated.

# Simulation end

$ns at 20.0 “finish”

proc finish {} {

global ns tracefile

$ns flush-trace

close $tracefile

exit 0

}

$ns run

After executing the simulation, we can evaluate the trace file for key parameters such as:

  • Packet delivery ratio (PDR)
  • Average delay
  • Energy consumption
  • Throughput

In this above following step-by-step procedure will completely help you to implement the Visual Sensor Network in ns2 environment that has efficiently capture, process and communicate with wireless senor nodes. We plan to provide the detailed information on how the visual sensor network will perform in other simulation scenarios. Our specialists is here to help you come up with the best thesis ideas and topics that match your interests. If you’re looking for great results with Network VSN implementation, feel free to reach out to the ns2project.com team.