Architecture

BLE problems often come from mixing phases, roles, and permissions into one bucket: being visible in a scan is not the same as being connected; being connected is not the same as being encrypted or ready for application data; and a successful mobile API callback does not mean every layer on the air interface and in the stack completed as expected.

If those boundaries are not separated early, later reading of GAP (Generic Access Profile), GATT (Generic Attribute Profile), ATT (Attribute Protocol), SMP (Security Manager Protocol), and Link Layer quickly collapses into one vague phrase: “the Bluetooth connection flow.”