Question - How many devices can communicate concurrently?
Answer -
A Bluetooth device playing the role of the “master” can communicate with up to 7 devices playing the role of the “slave”. This network of “group of up to 8 devices” (1 master + 7 slaves) is called a piconet. A piconet is an ad-hoc computer network of devices using Bluetooth technology protocols to allow one master device to interconnect with up to seven active slave devices (because a three-bit MAC address is used). Up to 255 further slave devices can be inactive, or parked, which the master device can bring into active status at any time.