This document discusses the key interfaces, architecture, and procedures related to control and user planes, mobility management, and connection management in 3G networks. The control plane handles protocols for controlling radio access bearers and the connection between UE and network. It has physical, data link, and network layers. The user plane is responsible for transferring user data through access and core network protocols. Mobility management allows tracking and delivering services to mobile subscribers via location management, registration, and security functions. Connection management establishes and maintains connections to exchange information with peer entities.