Bluetooth Virtual Laboratory

Explore wireless personal area networks through interactive simulations

Learning Objectives

  • • Understand Bluetooth protocol stack architecture (PHY, LL, HCI, L2CAP, ATT, GATT, SMP, GAP)
  • • Analyze frequency hopping spread spectrum (FHSS) and adaptive frequency hopping (AFH)
  • • Compare Bluetooth Classic (BR/EDR) vs Bluetooth Low Energy (BLE) characteristics
  • • Examine piconet and scatternet topology formations
  • • Calculate link budget and analyze path loss in 2.4 GHz ISM band

Prerequisites

  • • Basic understanding of wireless communication principles
  • • Familiarity with modulation techniques (GFSK, π/4-DQPSK)
  • • Knowledge of spread spectrum techniques
  • • Understanding of OSI model and protocol layering

Theoretical Background

1. Bluetooth Technology Overview

Bluetooth is a wireless technology standard for exchanging data over short distances using short-wavelength UHF radio waves in the ISM band from 2.400 to 2.485 GHz. It was originally conceived as a wireless alternative to RS-232 data cables.

Bluetooth Classic (BR/EDR)

  • • 79 channels, 1 MHz spacing
  • • Data rates: 1-3 Mbps
  • • Modulation: GFSK, π/4-DQPSK, 8DPSK
  • • Primary use: Audio streaming, data transfer

Bluetooth Low Energy (BLE)

  • • 40 channels, 2 MHz spacing
  • • Data rates: 125 kbps - 2 Mbps
  • • Modulation: GFSK
  • • Primary use: IoT, beacons, low-power sensors

2. Bluetooth Protocol Stack

Application
Profiles (A2DP, HFP, GATT, etc.)
Host
ATT, GATT, SMP, GAP, L2CAP
HCI
Host Controller Interface
Controller
Link Layer (LL), Physical Layer (PHY)

3. Network Topology

Piconet

A piconet consists of one master device and up to 7 active slave devices (Bluetooth Classic) or multiple slaves (BLE). All devices share the same frequency hopping sequence.

Master determines hopping sequence
Slaves synchronize to master's clock

Scatternet

A scatternet is formed when a device participates in multiple piconets. A device can be a slave in multiple piconets or a master in one and slave in another.

Bridge devices enable inter-piconet communication
Time-division multiplexing between piconets

4. Frequency Hopping Spread Spectrum (FHSS)

Bluetooth uses FHSS to minimize interference and enable multiple piconets to coexist. The hopping rate is 1600 hops/second (every 625 μs).

Channel Selection Algorithm:
k_next = (k_current + hop_increment) mod 79
Hop increment determined by master device address and clock

Laboratory Procedure

1

Topology Visualization

Navigate to the Simulation tab and select "Network Topology". Observe how the master device (central) coordinates communication with slave devices (peripherals). Note the TDD (Time Division Duplex) structure.

2

Frequency Hopping Analysis

Select "Frequency Hopping" simulation. Adjust the number of channels and observe the hopping pattern. Calculate the probability of collision with WiFi channels (channels 1, 6, 11).

3

Link Budget Calculation

Use the Link Budget calculator to determine maximum range. Vary transmit power, receiver sensitivity, and environmental factors. Record the calculated vs simulated range.

4

Packet Analysis

Examine BLE advertisement packets and data packets. Identify the Access Address, PDU, and CRC fields. Measure payload efficiency for different packet lengths.

5

Modulation Analysis

Observe GFSK modulation with different modulation indices (h = 0.5 for BLE). Compare with other modulation schemes and analyze spectral efficiency.

Simulation Controls

Status: Ready
Time: 0.00s
Throughput
--
Latency
--
SNR
--
BER
--

Laboratory Report Guidelines

Required Sections

1
Title Page
Experiment title, date, student name, ID
2
Objectives
Clear statement of learning goals
3
Theory
Bluetooth architecture, FHSS, piconet/scatternet
4
Procedure
Step-by-step simulation execution
5
Results & Analysis
Screenshots, graphs, calculations
6
Conclusion
Summary of findings and insights

Specific Requirements

Topology Analysis

Include screenshots of piconet formation with 3, 5, and 7 slaves. Calculate the polling interval for each configuration.

Frequency Hopping

Plot the hopping sequence for 20 hops. Calculate the dwell time and hopping rate.

Link Budget

Calculate maximum range for Class 1, 2, and 3 Bluetooth devices. Compare with simulation results.

Packet Efficiency

Calculate overhead percentage for different packet types. Analyze payload vs. header ratio.

Important

All calculations must show complete formulas and units. Graphs must have labeled axes with proper scales.