Bluetooth Protocols
Data Link Layer or Application Layer based on their functionality.
Bluetooth Protocol Stacks
Bluetooth protocols are categorized into two main stacks:
- Controller Stack – Handles low-level operations such as radio communication, packet handling, and encryption.
- Host Stack – Manages high-level communication, service discovery, and application-layer interactions.
| Controller Stack Protocols | Description |
|---|---|
| LMP (Link Management Protocol) | Manages link setup, authentication, encryption, and power control. |
| LE LL (Low Energy Link Layer) | Handles BLE advertisement, scanning, connection, and security. |
| SCO (Synchronous Connection-Oriented Link) | Ensures real-time voice data transmission with reserved time slots. |
| ACL (Asynchronous Connection-Less Link) | Standard data link using polling TDMA for packet transfer. |
| HCI (Host Controller Interface) | Defines the interface between the host stack and controller hardware. |
| Host Stack Protocols | Description |
|---|---|
| L2CAP (Logical Link Control and Adaptation Protocol) | Manages data multiplexing, segmentation, and reassembly. |
| RFCOMM (Radio Frequency Communication) | Emulates serial port communication over Bluetooth. |
| SDP (Service Discovery Protocol) | Allows devices to discover available Bluetooth services. |
| AVDTP (Audio/Video Distribution Transport Protocol) | Handles streaming of multimedia data. |
| A2DP (Advanced Audio Distribution Profile) | Supports high-quality audio streaming. |
| HID (Human Interface Device) | Enables input devices like keyboards, mice, and game controllers. |
| OBEX (Object Exchange) | Supports binary object exchange (e.g., file transfer). |
| GATT (Generic Attribute Profile) | Manages BLE data structure and service interactions. |
| ATT (Attribute Protocol) | Defines how BLE devices store and access data. |
| SMP (Security Manager Protocol) | Manages pairing, encryption, and authentication for BLE. |
| BNEP (Bluetooth Network Encapsulation Protocol) | Supports networking over Bluetooth (e.g., PAN profile). |
| TCS (Telephony Control Protocol) | Controls call setup and management for voice communication. |
| AVCTP (Audio/Video Control Transport Protocol) | Used for remote control of audio/video devices. |