How to make a BLE mesh network?

Question

I had been wondering how wireless earbuds work and came across this image. I do not know how to replicate what is shown in the following image and would like to learn how to do it.

My end goal is to be able to have the smartphone connect to a device, while still being able to play music to a Bluetooth Headphone. I read into BLE 4.1 mesh and I am not sure if that would help either.

I have made images for the possible ways the multiple devices could communicate but I don't have enough reputation to attach the xD. I will try my best to describe them.

1) All devices manage to simultaneously communication with the smartphone.
2) All devices connect to a hub which relays data to the smartphone.
3) One device is the hub itself and relays data for all other devices while sending its own data.
4) The devices relay information for each other till the smartphone receives the data it called for.
5) Another possibility is to have a mesh structure where the devices relay all messages broadcast-ed over the network until the device for which the message is meant for, receives it.

I hope to make a project where a Bluetooth device I make does not hinder the user from connecting and using other Bluetooth devices simultaneously.

Thanks for reading and I look forward to any and all responses.

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Answer 1

You need to consider few things first.

• Since version 4.0 Bluetooth specification contains "Classic Bluetooth, Bluetooth high speed and Bluetooth low energy (BLE) protocols."
• Bluetooth Classic provides profiles like A2DP, AVRCP that are usually implemented by Bluetooth earbuds or speakers.
• BLE on the other hand communicates using GATT (a general specification for sending and receiving short pieces of data known as attributes over a low energy link).
• BLE is not designed to handle high bandwidth scenarios like Audio.

Now getting to a point

• You can have a smartphone connected to your earbuds with A2DP profile and simultaneously connected to several BLE devices.
• One or more of these BLE devices can realize mesh connectivity