Wikipedia
NBAP
In the 3GPP UTRAN architecture, NBAP (Node B Application Part) is the signalling protocol responsible for the control of the Node B by the RNC. NBAP is subdivided into Common and Dedicated NBAP (C-NBAP and D-NBAP), where Common NBAP controls overall Node B functionality, and Dedicated NBAP controls radio links to specific user equipment. NBAP forms part of the Iub interface.
NBAP handles two kind of Procedures for different NBAP functionalities Common Procedures for Managing Logical O & M Functions for Controlling BCCH Broadcast for creating new Node B Communication Context Dedicated Procedures for handling procedures of an existing Node B Communication Context in a TTP/CCP