From Beginner to Expert: A Comprehensive Analysis of Bluetooth Protocols

Bluetooth technology has permeated our lives widely: wireless headphones, smartwatches, game controllers, in-car voice systems, IoT devices… But do you really understand what Bluetooth protocols your devices support, how fast they are, and how far they can transmit? This blog will systematically guide you through the history and technical differences of Bluetooth protocols.

1. Background of Bluetooth Technology: From Audio Jumpers to the Hub of Everything Connected

Bluetooth (Bluetooth) technology was first proposed by Ericsson in 1994, aiming to replace serial and short-distance cable transmission solutions. With the explosion of wireless audio, the Internet of Things, and smart wearables, it has gradually evolved into a low-power, short-range, low-latency, multi-purpose communication standard.

The Bluetooth Special Interest Group (Bluetooth SIG) currently has over 35,000 member manufacturers, including Apple, Huawei, Microsoft, Intel, Qualcomm, Nordic, etc., which formulate protocols and promote hardware and system support.

2. Three Core Types of Bluetooth Protocol Family

Bluetooth is not a single protocol but a family of protocols, mainly divided into three categories:

Protocol Type

Abbreviation

Application Area

Characteristics

Classic Bluetooth

BR/EDR

Audio, Keyboard/Mouse, File Transfer

Stable, High Bandwidth, High Power Consumption

Low Energy Bluetooth

BLE

IoT, Wearables, Smart Home

Energy-efficient, High Concurrency, Short Data

Bluetooth Mesh

Mesh

Multi-node Communication, Smart Lighting Control

Strong Networking Capability, Low Bandwidth

3. Comparison of Bandwidth, Distance, and Applicable Scenarios of Different Protocols

Protocol

Bluetooth Version Start

Theoretical Rate

Actual Rate

Typical Distance

Application Example

BR (Basic Rate)

v1.0+

1 Mbps

~720 Kbps

10 meters

Old Bluetooth Keyboards/Serial Modules

EDR (Enhanced Data Rate)

v2.0+

3 Mbps

~2.1 Mbps

10-20 meters

Bluetooth Headsets, In-car Devices

BLE (Low Energy Bluetooth)

v4.0+

1 Mbps

~0.5 Mbps

50 meters+

Wearables, Door Sensors, Temperature and Humidity Sensors

BLE 5.0+ (High-Speed Mode)

v5.0

2 Mbps

~1.5 Mbps

40-80 meters

High-speed IoT, Mobile/Watch Interconnection

BLE 5.0+ (Low-Speed Long-Distance Mode)

v5.0

125 Kbps / 500 Kbps

~0.1 Mbps

Up to 240 meters

Outdoor Positioning, Long-Distance Control

Bluetooth Mesh

v4.0 (based on BLE)

< 100 Kbps

~tens of Kbps

Multi-hop covering hundreds of meters

Smart Home/Building Control

⚠️ Note: Bandwidth is inversely proportional to distance, in the BLE protocol, if the long-distance mode is enabled, the rate will significantly decrease.

4. Overview of Common Bluetooth Protocols and Functions

Protocol Name

Type

Function

Application Example

A2DP

BR/EDR

High-Quality Audio Transmission

Bluetooth Headsets, Speakers

HFP/HSP

BR/EDR

Bluetooth Calling, Voice Control

In-car Systems

HID

BR/EDR

Mouse/Keyboard Control

Bluetooth Keyboards, Game Controllers

SPP

BR

Serial Port Transmission

Industrial Control Devices, Serial Modules

GATT

BLE

Data Service Protocol

Heart Rate, Temperature Sensors, etc.

LE Audio

BLE 5.2+

Next-Generation Audio Protocol (Multi-Device Broadcasting)

Hearing Aids, Shared Headphones

5. Bluetooth Versions and Support Capabilities: Understanding Device Performance at a Glance

Bluetooth Version

Release Year

Supported Protocols

Transmission Capability

Key Improvements

2.1+EDR

2007

BR/EDR

3 Mbps

Simplified Pairing

4.0

2010

BR/EDR + BLE

First Introduction of BLE

Launch of Low-Power Devices

4.2

2014

Same as Above

Supports IPv6

Stronger Privacy/Data Transmission

5.0

2016

BR/EDR + Enhanced BLE

2 Mbps / 240m

Supports Long Distance, Dual Rate

5.2

2020

Optimized BLE

Isochronous Audio

Supports LE Audio

5.3

2021

Enhanced BLE

Further Reduced Power Consumption

Optimized Broadcast Period Control

5.4

2023

BLE + Group Broadcasting

Strengthened IoT Direction

Better Adaptation for Large Node Broadcasting

6. How to Determine Which Bluetooth Protocols My Device Supports?

1. Check the Device Manual

  • Search for “Bluetooth 5.0 / 5.2 / BLE Support”

  • Key Protocol Support Fields: A2DP, LE Audio, Mesh, GATT, etc.

2. Windows Query Method

  • Open <span>Device Manager</span> → Bluetooth → Properties → Advanced

  • Check the <span>Firmware Version (LMP)</span> corresponding Bluetooth version:

LMP Version

Bluetooth Version

6.x

4.0

7.x

4.1

8.x

4.2

9.x

5.0

10.x

5.1

11.x

5.2

12.x

5.3

3. Third-Party Tools (Recommended)

  • nRF Connect (Android/iOS): Scan BLE Protocols and Services

  • Bluetooth Explorer (macOS)

  • Bluetooth Version Finder (Windows)

7. Bluetooth Protocol Application Recommendations: How to Choose Without Pitfalls?

Application Scenario

Recommended Protocol

Recommended Version

Daily Headphones/Calls

A2DP + HFP

BR/EDR, Recommended 5.0+

Health Monitoring/Smart Bands

BLE (GATT)

Starting from 4.2, Recommended 5.2+

Low-Latency Audio/Shared Headphones

LE Audio (Isochronous)

Must be 5.2+

Smart Home Networking

BLE + Mesh

5.0+, Mesh Protocol Support

Bluetooth Serial Debugging

SPP

Above 2.1+EDR

Conclusion: Remember the Core Points of Bluetooth Protocols in One Sentence

Classic Bluetooth transmits quickly, BLE transmits efficiently, and Mesh transmits far, different devices and versions determine the limits of functionality and experience; it is not enough to just look at “supports Bluetooth” but also to consider “which protocols are supported”.

Additional Recommendations

If you are:

  • 🎧 User: Confirm support for BLE 5.2+, A2DP, LE Audio protocols when purchasing devices;

  • 💻 Technician: Pay attention to GATT table structure, security features, and low-power broadcast strategies when developing devices;

  • 🔧 Maintenance Personnel: Determine compatibility through version numbers and troubleshoot the root causes of unstable connections;

  • 🧠 Learner: You can think of Bluetooth protocols as a “road network” where different protocols are different lanes, with varying speeds, distances, and vehicles.

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