OCS
Online Charging System
The OCS is the main element of a service provider’s online (prepaid) billing architecture. In this capacity, the OCS interacts with a number of network nodes e.g. MSC, SGSN, PCEF, all of which can potentially provide billing related data. Core functions of the OCS include Rating (determining the units such as time, volume, etc in use and determining their price), subscriber account balance management, transaction control and advice of charge to external systems.