UMTS Interfaces & Protocols

Hello dears,

What are the most important 3G UMTS Interfaces and Protocolos?

Every 3G interface contains protocols used over it.
Most important are:

  1. Iub interface: Node B Application part protocol (NBAP).

  2. Iur interface: Radio Network Subsystem Application part protocol (RNSAP).

  3. Iu interface: Radio Access Network Application Part Protocol (RANAP).