Packet Data Network (PDN) SAE Gateway or PGW. So PGW is PDN SAE Gateway.
PGW provides connectivity from the UE to external packet data networks by being the point of entry/exit of traffic for the UE (User Equipment/mobile phone).
A UE may have simultaneous connectivity with more than one PGW for accessing multiple PDNs.
The PGW manages policy enforcement, packet filtration for users, charging support and lawful Interception.
WiMAX, CDMA 1X and EvDO.
Anchor for mobility in-
* Policy enforcement.
* Packet filtration for users.
* Charging support
* Lawful interception.