To simulate a Bluetooth Topology can be done by designing the behavior of Bluetooth devices and its communication using NS2 (Network Simulator 2). Bluetooth networks is also called as piconets that normally function in a star topology in which one device performs as the master, and able to seven other devices perform as slaves. To make a more complex Bluetooth environment, we can prolong the network by making the scatternets in which several piconets are interconnected.
While NS2 doesn’t have a dedicated Bluetooth module then we can estimate a Bluetooth topology utilising its wireless communication capabilities by modifying the metrics such as the MAC layer, PHY layer, and particular characteristics of Bluetooth communication.
Steps to Simulate Bluetooth Topology Projects in NS2
Step 1: Understand Bluetooth Topology
In a Bluetooth Topology:
- Piconet: A master node communicates with numerous slave nodes. Every communication runs through the master.
- Scatternet: Several piconets are interconnected, including a few devices are functioning as gateways among the piconets.
- Bluetooth operates within the 2.4 GHz ISM band, and connections usually have low range and moderate bandwidth.
Step 2: Design the Network
We will replicate a Bluetooth Piconet Topology in which:
- One device performs as the master, and various devices perform as slaves.
- The master manages communication and all data exchange among the slaves runs through the master.
Step 3: Create an NS2 TCL Script for Simulating Bluetooth Topology
Following is an NS2 TCL script, which replicates a Bluetooth Piconet Topology with a master device and several slave devices are communicating within a star formation.
Example: Bluetooth Piconet Topology Simulation in NS2
# Create a new NS2 simulator object
set ns [new Simulator]
# Define parameters for the Bluetooth-like wireless network
set opt(chan) Channel/WirelessChannel ;# Wireless channel type
set opt(prop) Propagation/TwoRayGround ;# Propagation model
set opt(netif) Phy/WirelessPhy ;# Physical layer model
set opt(mac) Mac/802_11 ;# Using 802.11 as an approximation for Bluetooth
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) 100 ;# X dimension of the grid (small for Bluetooth)
set opt(y) 100 ;# Y dimension of the grid
set opt(adhocRouting) AODV ;# Routing protocol (not required for direct master-slave)
# Create a topology object
set topo [new Topography]
$topo load_flatgrid $opt(x) $opt(y)
# General Operations Director (GOD) to manage nodes
create-god 8
# Configure node properties for Bluetooth-like behavior
$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 $topo \
-agentTrace ON \
-routerTrace ON \
-macTrace ON \
-movementTrace ON
# Create Bluetooth devices (1 master and 4 slaves)
set master [$ns node] ;# Master node (central in piconet)
set slave1 [$ns node] ;# Slave node 1
set slave2 [$ns node] ;# Slave node 2
set slave3 [$ns node] ;# Slave node 3
set slave4 [$ns node] ;# Slave node 4
# Position nodes (master in the center, slaves around it)
$master set X_ 50
$master set Y_ 50
$master set Z_ 0.0
$slave1 set X_ 60
$slave1 set Y_ 50
$slave1 set Z_ 0.0
$slave2 set X_ 40
$slave2 set Y_ 50
$slave2 set Z_ 0.0
$slave3 set X_ 50
$slave3 set Y_ 60
$slave3 set Z_ 0.0
$slave4 set X_ 50
$slave4 set Y_ 40
$slave4 set Z_ 0.0
# Attach UDP agents for communication between the master and slaves
set udp1 [new Agent/UDP]
set udp2 [new Agent/UDP]
set udp3 [new Agent/UDP]
set udp4 [new Agent/UDP]
# Attach UDP agents to master and slave nodes
$ns attach-agent $master $udp1
$ns attach-agent $master $udp2
$ns attach-agent $master $udp3
$ns attach-agent $master $udp4
# Attach Null agents to the slaves as sinks
set null1 [new Agent/Null]
set null2 [new Agent/Null]
set null3 [new Agent/Null]
set null4 [new Agent/Null]
$ns attach-agent $slave1 $null1
$ns attach-agent $slave2 $null2
$ns attach-agent $slave3 $null3
$ns attach-agent $slave4 $null4
# Connect UDP agents from master to slaves
$ns connect $udp1 $null1
$ns connect $udp2 $null2
$ns connect $udp3 $null3
$ns connect $udp4 $null4
# Create CBR traffic from the master to the slaves
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
set cbr3 [new Application/Traffic/CBR]
$cbr3 set packetSize_ 512
$cbr3 set interval_ 0.1
$cbr3 attach-agent $udp3
set cbr4 [new Application/Traffic/CBR]
$cbr4 set packetSize_ 512
$cbr4 set interval_ 0.1
$cbr4 attach-agent $udp4
# Start traffic flows
$ns at 1.0 “$cbr1 start”
$ns at 1.5 “$cbr2 start”
$ns at 2.0 “$cbr3 start”
$ns at 2.5 “$cbr4 start”
# Create trace and nam files for recording the simulation events
set tracefile [open “bluetooth_topology.tr” w]
$ns trace-all $tracefile
set namfile [open “bluetooth_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 bluetooth_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 set to Channel/WirelessChannel, including the TwoRayGround propagation model and 802.11 MAC layer utilized as estimation for Bluetooth behavior.
- Bluetooth Device Setup:
- Five Bluetooth devices are made they are one master and four slaves.
- These nodes are nearly located together within a small 100×100 grid to replicate the short-range communication usual of Bluetooth.
- Traffic Setup:
- UDP agents are connected to the master also the slave devices to replicate communication among the master and every single slave.
- Constant Bit Rate (CBR) traffic is made from the master to every single slave to mimic the constant data transfer amongst the master and the slaves.
- Tracing and Visualization:
- A trace file (bluetooth_topology.tr) is made to record all network events, like packet transmissions, receptions, and drops.
- A NAM file (bluetooth_topology.nam) is generated for envisioning the Bluetooth piconet and communication amongst devices.
Step 5: Run the Simulation
- We need to save the script as bluetooth_topology.tcl.
- Execute the script using NS2:
ns bluetooth_topology.tcl
It will make two files:
- bluetooth_topology.tr: A trace files, which records the packet-level information.
- bluetooth_topology.nam: In NAM, for envisioning the networks using the NAM file.
Step 6: Visualize the Simulation Using NAM
To envision the Bluetooth Piconet Topology in NAM:
nam bluetooth_topology.nam
In NAM, we will observe:
- The master node in the center including the slave nodes are organised around it.
- From the master to the slaves, a packet transmission as traffic flows from the master node to every single slave.
Step 7: Analyze the Trace File
The trace file (bluetooth_topology.tr) records every network events, like:
- Packet transmissions and receptions among the nodes.
- Packet drops or delays triggered by interference or bandwidth limitations.
We can utilize the tools such as AWK, Python, or custom scripts to examine the trace file and extract crucial parameters like:
- Packet delivery ratio (PDR).
- End-to-end delay among the master and slaves.
- Network throughput.
Step 8: Enhance the Simulation
Below is a few ways to prolong or improve the simulation:
- Add More Slaves or Create Scatternets: Append additional slave nodes to the piconet or make several interconnected piconets (scatternets).
- Simulate Mobility: Insert mobility models to replicate the moving Bluetooth devices and monitor how the communication modifies.
- Power Consumption: Include an energy models to replicate power usage that is crucial within Bluetooth devices.
- Simulate Link Failures: Launch link failures to replicate interference and monitor how it impacts the communication.
To conclude, we had clearly understood the concepts and we know from how to design the network to how to analyse their performance and enhance the simulation for Bluetooth Topology Projects through the given step-by-step method that is very helpful to you for implement these projects using NS2.
Contact us to explore more Bluetooth Topology Projects utilizing NS2, designed to meet your specific research simulation needs. We provide comprehensive guidance through our advanced tools and resources.
