Study And Implementation Of 3G OCS

OCS ,Online Charging System, Online or Realtime charging system, is an open and ubiquitous reference architecture for online charging, and it is advanced by 3GPP in the TS 32.296. It can provide online charging for bearer,event and session. Through the separation of the service control and charging function it can estalishe a direct interaction between the charging mechanism and the session/service control function, so the charging function can completely control the service usage process. In this architecture, it can provide not only the convergence charging ability for multiple networks and services , but also the online/realtime ability to minimize the cost of customers debiting risk ,eventually to decrease the loss of network operators' revenue. So, it is significant for the construction of the operators' charging system in the coming 3G era.This paper will firstly discuss the 3GPP OCS architecture, including its logical functionalities and interfaces between them. Then it will discuss the key technologies concerned by OCS,which include the protocols and the credit control models. For the remainder of the paper, we will advance a implementation system of OCS, which supports the online charging of several typical services of the IMS,MMS,CS and PS domain, including its system design and implementation strategy.