Offline Charging vs. Online Charging in LTE - Mobile Packet Core
The S2b interface is is a 4G interface between the PGW and ePDG.
Telecom Core Network - PertSol is a leading IT and Telecom solution and service provider for the Telecom Service Providers and government and law enforcement agencies
What is PGW in telecom? - Quora
Serving Gateway - an overview | ScienceDirect Topics