To be become a LTE Expert?

• Serving Gateway
– Routes user data to the appropriate eNodeB as the mobile moves
– Routing to an SGSN for 2G/3G access
• Packet Data Network (PDN) Gateway
– Routing of data to the external Packet Data Network
– Routing user data to WLAN (Wifi, WiMAX)
– For mobile to mobile calls - routes data to its peer
– Allocation of IP address to mobiles
– Links to PCRF for charging and operator policy enforcement (resource allocation and usage)

The Serving Gateway and PDN Gateway may be implemented in one node. Alternatively, the Serving Gateway could be joined with the MME.
If the mobile roams to a different network, the Serving gateway (that is linked with the local eNodeB) will communicate with the PDN Gateway for the mobile’s registered network. Also the local MME will have to communicate with the HSS of the mobile’s registered network to obtain security details (for authentication and ciphering control).
The PDN Gateway also performs packet filtering, inspection packets for
viruses.