To be become a LTE Expert?

• NAS Control plane functions related to the network attachment and session management
• Authentication
• Control of ciphering and integrity checking
• Signalling to establish a PS session
• Negotiation of QoS parameters
• Tracking Area Updates in Idle mode
• Mobility support in Active mode (handovers)
• Determination of the Serving and PDN Gateway

To permit handovers, the eNodeB can be linked to different Serving and PDN gateways, so the MME is used to determine the appropriate gateways when the radio bearers are setup