Should I use BLE (Bluetooth 5) or Classic Bluetooth?

Question

For my application, I need to send 84 bytes of data every 500 Hz from a data acquisition device to a host device. Is it possible to achieve this using Bluetooth 5 module available in market. Although Bluetooth 5 claims a 2 Mbps data rate, it is known that actual throughput could be less. Also, the host device(central) could also limit the data rate by using larger connection intervals. In this case, is it feasible solution to choose Bluetooth 5 module over a module with Bluetooth classic?

Answer 1

Is battery saving important in your project?

The main advantage of Bluetooth 5.0 over classic version is energy saving, security and operating range.

Bluetooth Classic can offer you 2 - 3 [Mbps]. Have you ever thought about wifi direct? It offers speed over 100 [Mbps].

This article will help you:

https://www.electronicdesign.com/industrial-automation/article/21808300/how-to-pick-the-best-bluetooth-protocol-for-your-application

Answer 2

You should combine multiple data to build a longer packet, to avoid overhead. For example, you should take two of your 84 byte long values and build a 168 byte long value.

If you have LE Data Length Extension enabled, then you can reach the throughput you need. See https://www.novelbits.io/bluetooth-5-speed-maximum-throughput/. Note that this assumes there is only one active connection by the central. If you need multiple connections, the throughput will drop drastically since it needs to divide the radio time to each connection.

If you are of control of the devices at both ends, you should be able to fulfill your throughput requirements. But if you want it to work with any regular smartphone, BLE will not work that good for your use case since many phones don't have LE Data Length Extension.

Note that "Bluetooth 5" does NOT mean BLE with 2MBit/s. Bluetooth 5 is just the specification that contains a collection of a bunch of optional radio protocols, that reflects the current development state in 2016. There are Bluetooth 5 devices that only have Bluetooth classic and there are Bluetooth 5 devices that only have the basic BLE features and no Bluetooth classic.