In UMTS one can find all mentioned objects and divisions.
As for the layers the Figure 1 shows what layers are defined for UMTS.
Figure 1. UMTS network protocols layers 
As mentioned in each layer may have its User and Control Plane. Each layer has dedicated protocol to work in proper plane. Detailed description of theses protocols will be placed in next posts.
Figure 2. General Layer, Plane and Protocol Model for interfaces in UTRAN 
Signaling bearers for Transport Network User Plane and for Transport Network Control Plane may be different but may be the same. It is up to configuration if the same Signaling Bearers would be used 
 UMTS System Telefonii Komórowej Trzeciej Generacji - J. Kołakowski, J. Cichocki. WKŁ 2006
 3GPP TS 25.401