Bluetooth is a standardized protocol for secure, low-power wireless communication over short distances, operating on a 2.4GHz frequency band. It uses a master/slave model within piconets to manage data flow, and supports various protocols across different layers to facilitate connections and services. Bluetooth has evolved through multiple versions, enabling enhancements in data rate, efficiency, and power consumption, particularly with Bluetooth Low Energy (BLE) for IoT applications.

1. BLUETOOTH
TECHNOLOGY
TEAM MEMBERS
HASWANTH SAHADEVAN K
MOHAMED SARFUDEEN M
LALITH MOHAN S
RASWANTH M
SANJAY V

2. INTRODUCTION TO BLUETOOTH
● Bluetooth is a standardized protocol for sending and receiving data via a 2.4GHz
wireless link.
● It's a secure protocol, and it's perfect for short-range, low-power, low-cost, wireless
transmissions between electronic devices.
● Bluetooth network technology connects mobile devices wirelessly over a short-range
to form a personal area network (PAN).
● Bluetooth serves as an excellent protocol for wirelessly transmitting relatively small
amounts of data over a short range (<100m).
● The Bluetooth architecture has its own independent model with a stack of protocols,
instead of following the standard OSI model or TCP/IP model.

3. HOST & CONTROLLER
A Bluetooth device is composed of two types of elements: a host and one or more controllers.
● Host: Serves as an interface for applications and the operating system and implements
the protocols of the higher layers. It communicates with the OS applications to perform
tasks with Bluetooth.
● Controller: Implements the basic functions and protocols of the stack and supports the
different Bluetooth technologies: BR/EDR and LE. A controller can support BR/EDR, LE, or
both combined.
● Host and controller communicate with each other using the HCI (Host Controller
Interface) packet transmission protocol, allowing the host to send actions to a controller
and receive events in response, controlling the state of communications at a high level.

4. HOST & CONTROLLER

5. THE BLUETOOTH ARCHITECTURE

6. PROTOCOLS IN THE BLUETOOTH ARCHITECTURE
● Physical Layer This includes Bluetooth radio and Baseband (also in the data link
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layer.
○ Radio This is a physical layer equivalent protocol that lays down the physical
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structure and specifications for transmission of radio waves. It defines air
interface, frequency bands, frequency hopping specifications, and modulation
techniques.
○ Baseband This protocol takes the services of radio protocol. It defines the
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addressing scheme, packet frame format, timing, and power control algorithms.

7. PROTOCOLS IN THE BLUETOOTH ARCHITECTURE
● Data Link Layer This includes Baseband, Link Manager Protocol (LMP), and Logical
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Link Control and Adaptation Protocol (L2CAP).
○ Link Manager Protocol (LMP) LMP establishes logical links between Bluetooth
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devices and maintains the links for enabling communications. The other main
functions of LMP are device authentication, message encryption, and negotiation
of packet sizes.
○ Logical Link Control and Adaptation Protocol (L2CAP) L2CAP provides adaption
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between upper layer frame and baseband layer frame format. L2CAP provides
support for both connection-oriented as well as connectionless services.

8. PROTOCOLS IN THE BLUETOOTH ARCHITECTURE
● Middleware Layer This includes Radio Frequency Communications (RFComm) protocol,
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adopted protocols, SDP, and AT commands.
○ RFComm It is short for Radio Frontend Component. It provides a serial interface with
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WAP.
○ Adopted Protocols These are the protocols that are adopted from standard models.
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The commonly adopted protocols used in Bluetooth are Point-to-Point Protocol (PPP),
Internet Protocol (IP), User Datagram Protocol (UDP), Transmission Control Protocol
(TCP), and Wireless Application Protocol (WAP).
○ Service Discovery Protocol (SDP) SDP takes care of service-related queries like device
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information so as to establish a connection between contending Bluetooth devices.
● Applications Layer This includes the application profiles that allow the user to interact with
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the Bluetooth applications.

9. MASTERS, SLAVES & PICONETS
● Bluetooth networks (commonly referred to as piconets) use a master/slave model to
control when and where devices can send data.
● The master initiates and manages connections, while slave devices respond to the
master’s commands.
● A piconet can contain up to 8 devices: 1 master and up to 7 active slaves, with the
potential for "parked" slaves that are inactive but synchronized.

10. MASTERS, SLAVES & PICONETS
● Only the master can control the flow of data, initiating all exchanges and determining
transmission timing.
● Devices can belong to multiple piconets, creating a "scatternet" where they act as a
slave in one piconet and as a master in another.
● The master/slave structure minimizes interference, allowing reliable data transmission
and efficient use of bandwidth.
● The master polls each slave to check for data, ensuring organized and collision-free
communication within the piconet.
● The master/slave model helps keep piconets small, limiting range and adding a level of
privacy within short-range connections.

11. BLUETOOTH FREQUENCY
● Bluetooth operates in the 2.4 GHz ISM band.
● It uses the frequency range from 2.402 GHz to 2.480 GHz.
● Bluetooth employs frequency hopping spread spectrum (FHSS), hopping between 79
channels (each 1 MHz wide) to reduce interference and improve reliability.
● If one particular frequency is experiencing interference (for example, from a Wi-Fi
network), Bluetooth can hop to a different frequency, maintaining the connection.

12. MODULATION TECHNIQUES
1. Gaussian Frequency-Shift Keying (GFSK)
● Used in: Bluetooth Classic (versions 1.0, 1.1, 1.2, and 2.0)
● GFSK is a type of frequency-shift keying where the frequency of the carrier signal is
changed based on the data being transmitted.
● To reduce interference with nearby channels, GFSK applies a Gaussian filter, which
smooths out the transitions between frequencies.
● It’s a power-efficient method, ideal for short-range wireless communication.
● The modulation is binary, meaning it uses two frequencies: one for a binary "0" and
another for a binary "1."
● GFSK is simpler to implement compared to more complex modulation schemes.

13. MODULATION TECHNIQUES
2. π/4-Differential Quadrature Phase Shift Keying (π/4-DQPSK)
● Used in: Bluetooth 2.0+EDR and late.
● In DQPSK, the phase of the carrier signal is shifted by different amounts to
represent multiple bits per symbol, increasing the data rate compared to GFSK.
● In π/4-DQPSK, the phase shifts are offset by π/4 (45°), creating 8 distinct phase
states, which increases the data rate compared to standard QPSK.
● π/4-DQPSK supports data rates up to 2 Mbps, making it suitable for higher-speed
Bluetooth communication.

14. CONNECTION PROCESS
Creating a Bluetooth connection between two devices is a multi-step process involving three
progressive states:
● Inquiry -- If two Bluetooth devices know absolutely nothing about each other, one must
run an inquiry to try to discover the other. One device sends out the inquiry request, and
any device listening for such a request will respond with its address, and possibly its
name and other information.
● Paging (Connecting) -- Paging is the process of forming a connection between two
Bluetooth devices. Before this connection can be initiated, each device needs to know the
address of the other (found in the inquiry process).
● Connection -- After a device has completed the paging process, it enters the connection
state. While connected, a device can either be actively participating or it can be put into a
low power sleep mode.

15. CONNECTION PROCESS
● Active Mode -- This is the regular connected mode, where the device is actively
transmitting or receiving data.
● Sniff Mode -- This is a power-saving mode, where the device is less active. It'll sleep and
only listen for transmissions at a set interval (e.g. every 100ms).
● Hold Mode -- Hold mode is a temporary, power-saving mode where a device sleeps for
a defined period and then returns back to active mode when that interval has passed.
The master can command a slave device to hold.
● Park Mode -- Park is the deepest of sleep modes. A master can command a slave to
"park", and that slave will become inactive until the master tells it to wake back up.

16. BONDING & PAIRING
● Bonds are created through one-time a process called pairing. When devices pair
up, they share their addresses, names, and profiles, and usually store them in
memory.
● They also share a common secret key, which allows them to bond whenever
they're together in the future.
● Pairing usually requires an authentication process where a user must validate
the connection between devices.

17. BLUETOOTH VERSIONS : BR/EDR
● BR/EDR: Also called Bluetooth Classic as it was the first to appear.
● Bluetooth BR (Basic Rate) is the first version of Bluetooth and was later extended
with EDR (Extended Data Rate), which allows for a higher maximum data
transmission rate.
○ Maximum transfer rate in Bluetooth Basic Rate (BR):
■ 1 Mbps (megabit per second)
○ Maximum transfer rates in Bluetooth Extended Data Rate (EDR):
■ 2 Mbps with EDR 2
■ 3 Mbps with EDR 3
● BR and EDR are fully compatible, so they are considered a single system and
referred to as BR/EDR.

18. BLUETOOTH VERSIONS : BLE
● Bluetooth LE (Low Energy) was later developed as a low-power alternative for simpler
and cheaper devices, initially with a lower data transmission rate than BR/EDR,
although in the latest versions of the protocol, they have increased to almost match
those of BR/EDR
● Maximum transfer rates in Bluetooth Low Energy (BLE):
○ Bluetooth 4.0 and 4.1: 1 Mbps
○ Bluetooth 5.0 and 5.1: 2 Mbps (doubled compared to previous versions)
○ Bluetooth 5.2: 2 Mbps (improvements in terms of data capacity, efficiency, and
range)
○ Bluetooth 5.3 and 5.4: 2 Mbps (improvements that increase efficiency, security,
and functionality)

19. ADVANTAGES OF BLUETOOTH TECHNOLOGY
● Bluetooth, especially Bluetooth Low Energy (BLE), is optimized for low power, making it
ideal for battery-operated devices like wearables and IoT sensors.
● Bluetooth is universally supported across a wide range of devices, from smartphones
and laptops to headphones and cars, ensuring cross-platform interoperability.
● Bluetooth mesh enables large-scale device networks, making it suitable for
applications like smart homes, lighting systems, and industrial automation.
● Bluetooth is ideal for creating small, personal networks where devices can
communicate without relying on external networks.

20. THANK YOU!