What is Bluetooth
Bluetooth is a wireless communication technology that is mainly used to achieve connection and data transmission between devices within a short distance. At present, whether in wireless headphones, smart watches, smart homes, or other IoT devices, Bluetooth connections play an important role. But in some special scenarios, we may need a longer transmission distance, so how to increase the communication distance of Bluetooth?
1 Increase the communication distance of Bluetooth from the hardware design
1.1 Antenna
The antenna is an important factor affecting the Bluetooth communication distance. A powerful antenna design can significantly improve the transmission capacity and coverage of the signal. When designing Bluetooth devices, device manufacturers usually choose the appropriate antenna type and position for different application scenarios to ensure the best signal reception and transmission effect. If you are using a DIY Bluetooth device, you can consider purchasing and installing a high-gain antenna to increase the transmission distance.
1.2 Signal amplifier
Signal amplifier is an effective means to enhance Bluetooth signals. By installing a signal amplifier, the transmission power of the signal can be increased, thereby increasing the transmission distance. There are a variety of Bluetooth signal amplifiers available on the market, and users can purchase and install them according to specific needs. It should be noted that when using a signal amplifier, the compatibility and legality of the device must be ensured to avoid interference with other wireless devices.
2 Increase the Bluetooth communication distance from the software level

2.1 Choose the right Bluetooth version

Bluetooth version

Description

Transmission distance

Bluetooth 1.x


Early version, short transmission distance

Generally 10m range

Bluetooth 2.x +EDR

Transmission distance increased, and EDR technology was introduced to increase transmission rate

General communication distance 30m

Bluetooth 3.x + HS

Introduction of high-speed mode, which can increase the transmission rate to 24Mbps, but the communication distance is reduced

Generally around 10m

Bluetooth 4.x

Introduction of low-power Bluetooth

Transmission distance around 50m

Bluetooth 5.x

Significantly increased transmission distance

Maximum 240m

So from the table above, we can see that choosing a higher version of the Bluetooth protocol can also increase the Bluetooth communication distance.
2.2 Adjust software parameters
You can choose a higher transmission power and a lower transmission rate to increase the Bluetooth transmission distance.
3 Increase communication distance at the environmental level
3.1 Reduce obstacles and environmental interference
Bluetooth signals are affected by obstacles and environmental factors during transmission. Walls, metal objects and other wireless signals will interfere with Bluetooth signals and reduce the transmission distance. In order to maximize the Bluetooth communication distance, obstacles on the signal transmission path should be minimized while avoiding interference from other wireless signals. If you use a Bluetooth device indoors, you can try to adjust the position of the device so that it is in a more open area for better signal reception.
3.2 Device maintenance
Regular maintenance and care of Bluetooth devices is also an important measure to ensure communication distance. Cleaning the antenna and contact points of the device to avoid the accumulation of dust and dirt can improve the transmission effect of the signal. In addition, regularly checking the battery and power supply of the device to ensure that the device is running in the best condition can also help increase the communication distance.
4 Choose the appropriate networking method
4.1 Use relay to increase Bluetooth communication distance
Based on the Bluetooth master-slave function, add the master-slave module as a relay to the connection, which can double the Bluetooth communication distance.

4.2 Based on Bluetooth mesh network

As shown in the figure, BLE Mesh uses a virus-like "infection" method to forward data. When the entire network is large enough, the communication distance between nodes in the network can be improved to a certain extent.
5 Summary
So in general, increasing the communication distance of Bluetooth is a process of comprehensive consideration from many aspects. In practical applications, it is necessary to flexibly select and combine these methods according to specific usage scenarios and needs to obtain the best transmission effect and user experience.