# Overview

Source: [https://docs.qualcomm.com/doc/80-58740-4/topic/overview.html](https://docs.qualcomm.com/doc/80-58740-4/topic/overview.html)

## Features supported by BLE

Bluetooth HOST feature

- Roles supported by GAP: Peripheral and Central, Observer, and Broadcaster
- Roles supported by GATT: Server and Client
- Supports pairing including secure connection features in Bluetooth 4.2
- Supports permanent storage of Bluetooth-specific settings and data

Bluetooth mesh features

- Supports Relay, Friend Node, Low-Power Node (LPN) and GATT Proxy roles
- Supports two types of Provisioning bearers (PB-ADV & PB-GATT)

## BLE protocol stack architecture

![](data:image/png;base64,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)  

There are 3 main layers in total, which together form a complete Bluetooth low energy
                protocol stack

- Host: This layer sits below the application and consists of multiple
                    (non-real-time) network and transport protocols that enable applications to
                    communicate with peer devices in a standard and interoperable manner.
- Controller: The controller implements the Link Layer (LE LL), a low-level
                    real-time protocol that together with the radio hardware provides standard
                    interoperability for over-the-air communications. The LL handles the reception
                    and transmission of packets, ensures data delivery, and handles all LL control
                    procedures.
- Radio hardware: Implements the required analog and digital baseband functional
                    blocks, allowing the link layer firmware to transmit and receive in the 2.4 GHz
                    band of the spectrum.

## Main control host

![](data:image/png;base64,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)  

The Bluetooth Host layer implements all high-level protocols and profiles, and most
                importantly it provides high-level APIs for applications.

- HCI: Host and controller interface
- L2CAP: Logical Link Control and Adaptation Protocol
- GATT: Generic Attribute Profile
- GAP: Generic Access Profile
- SMP: Security Manager Configuration Layer (Security Manager Specification)

## Application

The application layer is where users develop actual Bluetooth applications, including
                necessary protocol stack parameter settings and calls to various functional
                functions. We analyze it from two devices: Bluetooth slave and Bluetooth master.

Bluetooth slave

- Initialization of related hardware and basic services
- Set broadcast parameters: broadcast data, broadcast interval, scanning response
                    and other parameters or data
- Set Profile: add slave services, characteristic values, and set callback
                    functions to receive host data, and so on.
- Set pairing parameters (optional)
- Start the broadcast and start running
- Waiting for related events and event processing, such as receiving data from the
                    host, being linked, etc.

Bluetooth host

- Initialization of related hardware and basic services
- Set scanning parameters
- Set connection parameters
- Set pairing parameters (optional)
- Start the protocol stack and start running
- Waiting for related events and event processing, such as scanning events, slave
                    notify events, etc.

**Parent Topic:** [BLE](https://docs.qualcomm.com/doc/80-58740-4/topic/ble.html)

Last Published: Feb 10, 2025

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