How to Calculate Network Cluster head lifetime in NS2
To calculate the Network Cluster Head Lifetime in NS2 indicates the amount of time a cluster head node (accountable for handling communication inside its cluster) remains functional before its energy is depleted or before it is swapped by another node as the cluster head in a wireless sensor network (WSN). For any types of project help feel free to contact us we provide you with best results. Here in the below, we offered the procedure to calculate this in ns2:
General Steps to Simulate and Calculate Cluster Head Lifetime:
- Define a WSN Topology with Cluster Heads: In the simulation, state a pair of nodes that serve as cluster heads. These nodes will handle communication inside their clusters.
- Set Up the Energy Model: NS2’s energy model is used to allocate an initial energy to each node and record energy utilization. Cluster heads will usually use more energy during communication because of their role in gathering data and transferring it to the base station.
- Monitor Cluster Head Energy Consumption: Track the energy level of each cluster head and define when it run out of energy or is changed by another node.
- Calculate Cluster Head Lifetime: The lifetime of a cluster head is the time interval amongst when it becomes the cluster head and when it either runs out of energy or is replaced.
Example Tcl Script to Simulate Cluster Head Lifetime in NS2:
Below is an example of an NS2 script where a WSN with a cluster head is simulated, and the energy consumption of the cluster head is tracked to estimate its lifetime.
# Create a new simulator instance
set ns [new Simulator]
# Define the simulation area (X and Y dimensions)
set val(x) 500 ;# X dimension of the simulation area
set val(y) 500 ;# Y dimension of the simulation area
set val(stop) 20.0 ;# Simulation end time
# Create a topography object
set topo [new Topography]
$topo load_flatgrid $val(x) $val(y)
# Define wireless channel and propagation model
set chan_1_ [new Channel/WirelessChannel]
set prop_model [new Propagation/TwoRayGround]
# Energy model parameters
set val(initialEnergy) 100.0 ;# Initial energy in joules
set val(txPower) 0.5 ;# Transmission power in watts
set val(rxPower) 0.3 ;# Reception power in watts
set val(idlePower) 0.01 ;# Idle power in watts
# Configure sensor nodes with energy model
$ns node-config -adhocRouting AODV \
-llType LL \
-macType Mac/802_11 \
-ifqType Queue/DropTail/PriQueue \
-ifqLen 50 \
-antType Antenna/OmniAntenna \
-propType Propagation/TwoRayGround \
-phyType Phy/WirelessPhy \
-topoInstance $topo \
-energyModel EnergyModel \
-initialEnergy $val(initialEnergy) \
-txPower $val(txPower) \
-rxPower $val(rxPower) \
-idlePower $val(idlePower) \
-channel $chan_1_ \
-agentTrace ON \
-routerTrace ON \
-macTrace ON
# Create 10 sensor nodes (one of them will be the cluster head)
for {set i 0} {$i < 10} {incr i} {
set node($i) [$ns node]
$node($i) set X_ [expr {rand() * $val(x)}]
$node($i) set Y_ [expr {rand() * $val(y)}]
}
# Define node 0 as the cluster head
set clusterHead $node(0)
# Attach UDP agents to simulate communication
set udp0 [new Agent/UDP]
set null0 [new Agent/Null]
$ns attach-agent $node(1) $udp0
$ns attach-agent $clusterHead $null0
$ns connect $udp0 $null0
# Create a CBR traffic source to generate packets
set cbr0 [new Application/Traffic/CBR]
$cbr0 attach-agent $udp0
$cbr0 set packetSize_ 512
$cbr0 set rate_ 1Mb
# Start and stop traffic
$ns at 1.0 “$cbr0 start”
$ns at 15.0 “$cbr0 stop”
# Monitor the energy of the cluster head
proc monitor_cluster_head_energy {nodeID} {
global ns
set remaining_energy [$ns get-energy $nodeID]
puts “Cluster head (Node $nodeID) remaining energy: $remaining_energy J”
if { $remaining_energy <= 0.0 } {
puts “Cluster head (Node $nodeID) has died.”
exit 0
}
$ns at [expr [$ns now] + 1.0] “monitor_cluster_head_energy $nodeID”
}
# Start monitoring the energy of the cluster head
$ns at 1.0 “monitor_cluster_head_energy $clusterHead”
# Open trace file to log events
set tracefile [open trace.tr w]
$ns trace-all $tracefile
# Define finish procedure
proc finish {} {
global ns tracefile
$ns flush-trace
close $tracefile
exit 0
}
# End simulation
$ns at $val(stop) “finish”
$ns run
Explanation of the Script:
- Sensor Nodes and Cluster Head:
A wireless sensor network is generated with 10 sensor nodes. Node 0 is designated as the cluster head. - Energy Model:
An energy model is accomplished to all nodes with initial energy set to 100 joules, and power consumption values for transmission, reception, and idle states are stated. - Traffic Generation:
Node 1 sends packets to the cluster head (node 0) using a UDP agent and a CBR traffic source. - Monitoring Cluster Head Energy:
The function monitor_cluster_head_energy confirms the remaining energy of the cluster head every second. If the energy reaches zero, the node is considered dead, and the simulation logs the event.
- Trace File Analysis for Cluster Head Lifetime:
Once the simulation is done, you can extract the cluster head’s lifetime from the trace file by looking at when it first became the cluster head and when it died because of energy depletion.
Example Trace File Output:
r 1.0 _0_ AGT — 512 [0 0 0 0] ——- [0:0 1:0 32 0]
…
Energy of node 0: 50.0 J
Energy of node 0: 10.0 J
Cluster head (Node 0) has died.
In this instance, node 0 begins with 100 joules and gradually depletes its energy because of transmission and reception behaviors. The moment it runs out of energy, the simulation logs the event.
- Calculating Cluster Head Lifetime:
The lifetime of the cluster head can be estimated as the time amongst when it initiates functioning as the cluster head and when its energy depletes.
For example:
- If node 0 becomes the cluster head at time 1.0 seconds and dies at time 15.0 seconds, its lifetime would be: Cluster Head Lifetime=15.0−1.0=14.0 seconds\text{Cluster Head Lifetime} = 15.0 – 1.0 = 14.0 \, \text{seconds}Cluster Head Lifetime=15.0−1.0=14.0seconds
- Bash Script to Calculate Cluster Head Lifetime:
# Extract the time when the cluster head died from the trace log
death_time=$(grep “Cluster head.*has died” trace.tr | awk ‘{print $4}’)
# Calculate cluster head lifetime (assuming cluster head starts at 1.0s)
start_time=1.0
lifetime=$(echo “$death_time – $start_time” | bc)
echo “Cluster Head Lifetime: $lifetime seconds”
This script calculates the cluster head’s lifetime in terms of the time it runs out of energy.
Summary of Steps:
- Set Up a WSN with Cluster Heads: State a WSN topology where particular nodes behave like cluster heads.
- Implement Energy Model: Use NS2’s energy model to record the energy consumption of nodes.
- Monitor Cluster Head Energy: Continuously observe the energy of the cluster head and log when it runs out of energy.
- Calculate Cluster Head Lifetime: The cluster head lifetime is the time from when the node starts performing as the cluster head until its energy is depleted.
We have completely focused on the computation regarding Cluster Head Lifetime of the Network within the ns2 tool and snippet codes by establishing an energy model to monitor the consumption of energy during the operations through the detailed structure.