I'm getting confused with the following statement, taken from www.nordicsemi.com/.../S132
"It supports up to 20 concurrent links in all roles."
So, I will try to explain the use cases behind it, and what is possible and what not.
a) Per Bluetooth Specification, there is always only a one-to-one connection possible between physical devices (e.g. NRF52 chip)
b) Even in a Mesh network, only a one-to-one connection is provided, but each physical device can act as a master (in GAP Layer it is called CENTRAL) and slave (in GAP Layer it is called PERIPHERAL). So each device is able to advertise (PERIPHERAL role) and to scan/connect to another device (CENTRAL role).
c) It is always only possible to establish ONE connection between a PERIPHERAL and a CENTRAL.
d) A CENTRAL can connect to MULTIPLE physically devices, if these are PERIPHERALS
e) But, a PERIPHERAL can't have multiple connections (or links) to different CENTRALS, because this would be against the BLE specification.
Coming back to the statement and my confusion. Wouldn't it better to say: Up to 20 concurrent connections (links) in CENTRAL mode, instead saying "in all roles"?, because a PERIPHERAL can only have ONE and only ONE connection (link) at the same time to a CENTRAL device.
Please correct me, if some statement is wrong.
Thanks