# Bluetooth features

The WCN6750, WCN6856, and QCA6698AQ connectivity chipsets comply with the *Bluetooth Core specification v5.2*. These chipsets have the following controller features and capabilities:

- A Bluetooth Low Energy data rate of up to 2 Mbps
- A long-range mode with better sensitivity at two new lower bit rates, 500 Kbps and 125 Kbps
- An 8x improvement in broadcast capability with the use of advertising extensions
- An improved channel selection algorithm (CSA #2), which facilitates improved channel coordination and coexistence efficiency with other Bluetooth and non-Bluetooth traffic

The following table lists the Bluetooth specifications and features supported by the WCN6750, WCN6856, and QCA6698AQ connectivity chipsets.

| Feature | WCN6750 | WCN6856 | QCA6698AQ |
| --- | --- | --- | --- |
| Bluetooth Low Energy secure connections | <br>**✓** | <br>**✓** | <br>**✓** |
| Bluetooth Low Energy privacy 1.2 | <br>**✓** | <br>**✓** | <br>**✓** |
| Bluetooth 5.2 Core specification | <br>**✓** | <br>**✓** | <br>**✓** |
| Data length extensions | <br>**✓** | <br>**✓** | <br>**✓** |
| 2 Mbps PHY | <br>**✓** | <br>**✓** | <br>**✓** |
| Advertising extensions | <br>**✓** | <br>**✓** | <br>**✓** |
| Bluetooth Low Energy long range | <br>**✓** | <br>**✓** | <br>**✓** |
| CSA #2 | <br>**✓** | <br>**✓** | <br>**✓** |
| USB 1.1 interface support | <br>**✕** | <br>**✓** | <br>**✓** |

## BlueZ stack

BlueZ is a Bluetooth Linux stack that supports the core Bluetooth layers and protocols. BlueZ features are as follows:

- Complies with *Bluetooth Core specification v5.2*
- Supports multiple Bluetooth devices
- Implements a socket interface for all layers
- Supports multithreaded data processing

## Bluetooth profiles and roles

The Bluetooth profiles define the specifications, requirements, and roles of devices to establish a Bluetooth connection. A profile also determines the communication protocol used between devices.

The BlueZ stack supports the following Bluetooth profiles and roles for connectivity chipsets.

| <br>Profile | <br>Role | <br>Version | <br>Support on chipset | <br>Support on chipset |
| --- | --- | --- | --- | --- |
| <br>Profile | <br>Role | <br>Version | WCN6750/<br>WCN6856 | QCA6698AQ |
| General Access Profile (GAP) | Central and peripheral |  | <br>**✓** | <br>**✓** |
| Serial Port Profile (SPP) | Client and server | v1.2 | <br>**✓** | <br>**✓** |
| Human interface device (HID) over GATT Profile (HOGP) | Host | v1 | <br>**✓** | <br>**✓** |
| General Attribute Profile (GATT) | Central and peripheral |  | <br>**✓** | <br>**✓** |
| <br>Advanced Audio Distribution Profile (A2DP) | Source | Nonsplit v1.3 | <br>**✓** | <br>**✕** |
| <br>Advanced Audio Distribution Profile (A2DP) | Sink | Nonsplit v1.3 | <br>**✓** | <br>**✕** |
| <br>Audio/Video Remote Control Profile (AVRCP) | Target | v1.5 | <br>**✓** | <br>**✕** |
| <br>Audio/Video Remote Control Profile (AVRCP) | Controller | v1.5 | <br>**✓** | <br>**✕** |
| <br>Hands-Free Profile (HFP) | Audio gateway | Nonsplit v1.7 | <br>**✓** | <br>**✕** |
| <br>Hands-Free Profile (HFP) | Client | Nonsplit v1.7 | <br>**✓** | <br>**✕** |
| Object Push Profile (OPP) | Client and server | v1.2 | <br>**✓** | <br>**✓** |
| File Transfer Protocol (FTP) | Client and server | v1.2 | <br>**✓** | <br>**✓** |
| Phone Book Access Profile (PBAP) | Client and server | v1.1 | <br>**✓** | <br>**✓** |
| Message Access Profile (MAP) | Client and server | v1.2 | <br>**✓** | <br>**✓** |
|  |  |  |  |  |

Note

Bluetooth profile concurrency is supported.

### General Access Profile

Bluetooth Low Energy GAP is an extension of the existing BR/EDR GAP. It handles the following basic operations of a device:

- Discover a device
- Establish a connection
- Bond multiple devices
- Establish a private connection
- Resolve private addresses

All Bluetooth devices must implement a basic level of functionality that GAP defines. GAP ensures that all Bluetooth devices can establish baseband connections, regardless of the higher-level functionality they support. GAP is responsible for the following functions:

- Generic procedures for discovering Bluetooth devices
- Link-management aspects for connecting to Bluetooth devices
- Procedures related to security levels
- Common formats for user interface-level parameters, such as naming conventions

GAP defines and assigns the following profile roles to the devices.

| Profile role | Description |
| --- | --- |
| Central | <ul><br><li><p>A device with relatively greater processing power and memory.</p><br><p>For example, a mobile phone or a tablet.</p><br></li><br><li><p>Always a primary device.</p></li><br><li><p>It does’nt advertise.</p></li><br><li><p>Supports active or passive scanning and all link layer control procedures.</p></li><br></ul> |
| Peripheral | <ul><br><li><p>A small, low-power, and resource-contained device that can connect to a much more powerful central device.</p><br><p>For example, an instrument like a heart rate monitor, or a Bluetooth Low Energy enabled proximity tag.</p><br></li><br><li><p>Always a secondary device.</p></li><br><li><p>Advertises over connections.</p></li><br><li><p>Supports all link layer control procedures.</p></li><br></ul> |
| Broadcaster | <ul class="simple"><br><li><p>Sends nonconnectable advertising events including characteristics and service data.</p></li><br><li><p>It doesn’t require a receiver.</p></li><br></ul> |
| Observer | <ul class="simple"><br><li><p>Receives advertising events and listens for characteristics and service data.</p></li><br><li><p>It doesn’t require a transmitter.</p></li><br></ul> |

### Serial Port Profile

SPP facilitates wireless communication between devices over a virtual serial port. It supports client and server roles.

SPP defines the following elements:

- Requirements of Bluetooth devices to set up emulated serial cable connections using Radio Frequency Communication (RFCOMM) between two peer devices.
- Terms of services provided to applications.
- Features and procedures for interoperability between Bluetooth devices.

### General Attribute Profile

GATT is a service framework that uses the Attribute Protocol (ATT) to discover services, and to read and write characteristic values on a peer device. It supports client and server roles.

GATT performs the following functions:

- Interfaces with the application through application profiles.

    The application profile defines the collection of attributes and any permissions required for the attributes used in communication between devices.
- Specifies how two Bluetooth Low Energy devices exchange data using services or declarations, characteristics, and descriptors.

    It doesn’t define rules for attribute use. The upper-layer applications derive functionality by using these concepts.
- Stores services, characteristics, and related data in a basic lookup table, with 16‑bit IDs assigned to each entry.

### Human Interface Device over GATT Profile

HOGP defines how a Bluetooth Low Energy wireless communications device can support HID services over the Bluetooth Low Energy protocol stack using GATT.

### Advanced Audio Distribution Profile

A2DP defines the requirements to transmit or stream high-quality audio from one device to another over a Bluetooth connection. For example, streaming music from a mobile phone, laptop, or desktop to a wireless headset, and streaming audio to a hearing aid, cochlear implant, or car console.

A2DP supports the following roles.

| Profile role | Description |
| --- | --- |
| Source | <ul class="simple"><br><li><p>An audio source that streams digitally to the sink of the piconet.</p></li><br><li><p>Facilitates streaming of stereo-quality audio from a multimedia player to a wireless headset or speakers.</p></li><br></ul> |
| Sink | <ul class="simple"><br><li><p>An audio receiver device in a wireless audio setup.</p></li><br><li><p>Compresses audio data using audio codecs and then decodes at the speaker with minimal loss.</p></li><br><li><p>Supports high-quality, wireless audio playback and offers a convenient way to enhance the audio experience.</p></li><br></ul> |

### Hands-Free Profile

HFP defines how an audio gateway device can connect to a hands-free device for functions like remote control and audio connection.

HFP defines and assigns the following profile roles to the devices.

| Profile role | Description |
| --- | --- |
| Client | <ul class="simple"><br><li><p>A hands-free device. For example, a wireless headset or a vehicle console.</p></li><br><li><p>Establishes service level connections, creates an audio connection with a remote audio gateway, and transports dual-tone multifrequency (DTMF) codes.</p></li><br><li><p>Supports functionalities like answering or rejecting an incoming call, dialing a number, and controlling the volume.</p></li><br></ul> |
| Audio gateway | <ul class="simple"><br><li><p>A gateway for audio input and output. For example, a mobile phone.</p></li><br><li><p>Communicates with a hands-free device, which controls the audio mechanism and other functions of the audio gateway remotely.</p></li><br></ul> |

### Object Push Profile

OPP defines how two Bluetooth devices can exchange objects, such as business cards, images, wallpapers, ringtones, or videos. It allows a Bluetooth device to:

- Pull an object from another Bluetooth device.
- Push an object to another Bluetooth device.
- Exchange objects with another Bluetooth device.

OPP supports client and server roles.

### File Transfer Protocol

FTP defines the requirements to exchange files between two Bluetooth devices. FTP supports client and server roles. It allows a Bluetooth device to:

- Browse the files and folders of another Bluetooth device.
- Exchange files and folders with another Bluetooth device.
- Create or delete files and folders on another Bluetooth device.

### Phone Book Access Profile

PBAP facilitates the exchange of phone book objects between a remote and a local device. It’s based on a client-server interaction model where the client device gets the phone book objects from the server device. In the BlueZ stack, PBAP supports the following roles:

- Phone book server equipment (PSE): Consists of the source phone book objects.
- Phone book client equipment (PCE): Retrieves phone book objects from the PSE.

The types of phone book objects are listed as follows.

| Phone book object | Description |
| --- | --- |
| Main phone book | Phone book of the device, such as a mobile phone. |
| Incoming call history | List of most recently received calls. |
| Outgoing call history | List of most recently made calls. |
| Missed call history | List of most recently missed calls. |
| Combined call history | List of most recently received, made, or missed calls. |
| Speed-dial contacts | List of speed dial entries on the PSE. |
| Favorite contacts | List of favorite contacts on the PSE. |

PBAP allows the following functions:

- Download contacts and call histories from a remote device.
- Browse contacts on a remote device.
- Select a phone book object.

### Message Access Profile

MAP defines the features and procedures that devices use to exchange message objects. It’s based on a client-server interaction model where the client initiates the transactions. The types of message objects include electronic messages (Email) and short message service (SMS).

MAP combines the messaging capabilities of a messaging server device and the user interface capabilities of a client device to notify, browse, read, delete, generate, and send messages. In the BlueZ stack, MAP supports the following device roles:

- Message server equipment (MSE): Provides the message repository engine.
- Message client equipment (MCE): Uses the message repository engine of the MSE for MAP functions.

Last Published: Apr 02, 2025

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