Base Band 5, abbreviated as BB5, is the mobile baseband generation implemented on Nokia mobile phones and the replacement for prior DCT (Digital Core Technology) generations.
This generation of Nokia phone basebands uses a new range of chipsets, bus systems and components as well as enhanced security mechanisms preventing manipulations of firmware and system configurations. The phones' system interface has changed over from previous generations to allow, for instance, flashing of the device via USB.
In 2013, the BB5 platform was replaced with MediaTek and later Spreadtrum/UNISOC chips.