Through the use of carefully defined APIs, Interaction Methods and OO Class Libraries, the framework enables protocol software to be developed in a highly efficient way where each specific protocol element may be encapsulated as an independent runtime entity. In this way, multi-mode solutions can be implemented rapidly through efficient integration of separate stacks, even if separately sourced.  Alternatively, it becomes possible to evolve different layers of the stack at different rates, e.g. using a Release 9 NAS with a Release 8 LTE AS and a Release 7 W-CDMA AS.