@chaos_monster
@denladeside
@NordicTweets
@sherrrylst
@Espruino
@ZephyrIoT That is all part of the BLE Mesh
standard. I'm not the expert there, but you can get started here
https://www.nordicsemi.com/eng/Products/Bluetooth-low-energy/nRF5-SDK-for-Mesh
And if you have more questions, we run the biggest BLE community on the planet
at https://devzone.nordicsemi.com/ - you will find your answer there.