How to Start Bluetooth Topology Projects Using NS2

To start a Bluetooth Topology project in NS2 (Network Simulator 2) which requires replicating a Bluetooth network that functioning generally within a piconet or scatternet set up. Bluetooth networks are frequently leveraged for short-range wireless interaction among the devices such as smartphones, laptops, and other IoT devices.

We will need to replicate the Bluetooth networks in NS2 with the support of the Bluetooth extension that offers support for piconet such as single master, multiple slaves and scatternet (multiple piconets are linked via gateways) interaction. Below is a sequential method on how to start a Bluetooth Topology project in NS2:

Steps to Start Bluetooth Topology Projects in NS2

  1. Understand Bluetooth Topology
  • Bluetooth Topology:
    • Piconet: A small Bluetooth network including one master and equal to seven dynamic slave devices.
    • Scatternet: A network created by interconnecting numerous piconets through general nodes like gateways.
  • Applications:
    • IoT systems.
    • Personal area networks (PAN).
    • Audio streaming such as Bluetooth speakers, headsets.
  • Key Features:
    • Short-range communication (up to 100 meters).
    • Low power consumption.
    • Ad-hoc network design.
  1. Set Up NS2 for Bluetooth
  1. Install NS2:
    • We can set up and confirm NS2 with a basic script:

ns example.tcl

  1. Install Bluetooth Extension:
    • NS2 doesn’t offer direct support for Bluetooth thus we can set up the Bluetooth module/extension for NS2. This extension allows Bluetooth simulation like piconets and scatternets.
    • If the extension is not already installed, download it from the NS2 official website or a Bluetooth NS2 repository.
  2. Tools for Analysis:
    • NAM (Network Animator) is designed for envisioning the topology.
    • Trace Analysis Tools commonly utilised parameters such as latency, throughput, and packet delivery ratio (PDR).
  1. Plan the Bluetooth Topology
  • Network Design:
    • Piconet: It has one master and numerous slaves.
    • Scatternet: It contains several piconets, each piconets are connected via gateway nodes.
  • Metrics to Analyze:
    • Throughput.
    • Energy consumption as needed.
    • Packet Delivery Ratio (PDR).
    • Latency.
  1. Write the Simulation Script

Step 4.1: Create the TCL Script

We will need to store the tcl script like bluetooth_topology.tcl with NS2.

Step 4.2: Initialize the Simulator

Configure the simulator and tracing:

# Initialize the simulator

set ns [new Simulator]

set tracefile [open trace.tr w]

$ns trace-all $tracefile

set namfile [open bluetooth_topology.nam w]

$ns namtrace-all-wireless $namfile

Step 4.3: Create Bluetooth Devices

We can make Bluetooth devices that contains master and slave:

# Create Bluetooth devices (nodes in piconet)

set master [$ns node]

set slave1 [$ns node]

set slave2 [$ns node]

set slave3 [$ns node]

Step 4.4: Configure Links

In Bluetooth, interaction arise through the short-range radio connections. Configure the communication among devices:

# Create Bluetooth links (connections between master and slaves)

$ns duplex-link $master $slave1 1Mb 10ms DropTail

$ns duplex-link $master $slave2 1Mb 10ms DropTail

$ns duplex-link $master $slave3 1Mb 10ms DropTail

Step 4.5: Configure Traffic

Configure traffic flows among the master and slave devices:

# Traffic from master to slave1

set udp1 [new Agent/UDP]

$ns attach-agent $master $udp1

set null1 [new Agent/Null]

$ns attach-agent $slave1 $null1

$ns connect $udp1 $null1

set cbr1 [new Application/Traffic/CBR]

$cbr1 attach-agent $udp1

$cbr1 set packetSize_ 512

$cbr1 set rate_ 50kb

$ns at 1.0 “$cbr1 start”

# Traffic from master to slave2

set udp2 [new Agent/UDP]

$ns attach-agent $master $udp2

set null2 [new Agent/Null]

$ns attach-agent $slave2 $null2

$ns connect $udp2 $null2

set cbr2 [new Application/Traffic/CBR]

$cbr2 attach-agent $udp2

$cbr2 set packetSize_ 512

$cbr2 set rate_ 50kb

$ns at 2.0 “$cbr2 start”

Step 4.6: Enable Routing Protocol

Routing could not be obviously needed since it functions normally within a point-to-point manner within a piconet for Bluetooth communication. But, routing protocols such as AODV or DSR can be utilised for larger networks (scatternets).

# Example: Enable AODV routing protocol for larger Bluetooth networks

$ns rtproto AODV

Step 4.7: Finalize the Script

Integrate the simulation end conditions:

# End simulation

$ns at 10.0 “finish”

proc finish {} {

global ns tracefile namfile

$ns flush-trace

close $tracefile

close $namfile

exec nam bluetooth_topology.nam &

exit 0

}

$ns run

  1. Run the Simulation
  1. Now, we can store the tcl simulation script like bluetooth_topology.tcl.
  2. Run the script:

ns bluetooth_topology.tcl

  1. Go to NAM for envisioning the Bluetooth topology:

nam bluetooth_topology.nam

  1. Analyze Results
  • Trace File Analysis:
    • Estimate the metrics like throughput, latency, and PDR with the support of trace.tr.
    • Example AWK script for throughput:

awk ‘{if ($1 == “r” && $4 == “udp”) sum += $8} END {print “Throughput: “, sum}’

  • Metrics:
    • Packet Delivery Ratio (PDR): Assess how reliably packets are effectively distributed among the master and slaves.
    • Latency: Estimate the delay within interaction.
    • Throughput: Compute the rate of data in the communication.
  1. Expand the Simulation
  1. Add More Slaves:
    • We will need to integrate additional devices (slaves) for replicating a larger piconet.
  2. Simulate Scatternet:
    • Integrate numerous piconets for mimicking a scatternet in which nodes perform like gateways to other piconets.
  3. Add Mobility:
    • Allow node movement (random or directed), replicating the dynamic Bluetooth interaction:

$slave1 random-motion 1

  1. Simulate Node Failures:
    • Replicate the node or link failures, we can monitor the resilience of network:

$ns at 5.0 “$ns link-fail $master $slave1”

  1. Vary Traffic Patterns:
    • Launch diverse kinds of traffic models like multicast, broadcast, or higher-rate CBR (constant bit rate).
  1. Document the Project
  • Objective: Define the project’s goals that is replicating a Bluetooth topology.
  • Setup: It offers specifics regarding the nodes (master, slaves), links, and traffic.
  • Results: Provide performance parameters such as throughput, latency, and PDR for estimating the outcomes.
  • Conclusions: Sum up performance and potential enhancements.

In the end, we had discovered the basic simulation process on how to start and simulate the Bluetooth Topology Projects and analyse its performance using NS2 network simulator. If you need additional information about this topology we will share it.