Wireless Oom

Core Network (CN) is responsible for the higher functions such as user mobility, call control, session management, billing and security etc.
UMTS terrestrial radio access network (UTRAN) takes care of radio access, radio mobility and radio resource utilization.
User Equipment (UE).

Radio interface protocol structure:

Note that RB vs. SRB
At the UTRAN side, RLC and above protocols are located at RNC.
MAC protocols: some functionalities are at Node B, others are at RNC.