Section: 4.3.1.2 Charging Data Function
Content: The Charging Data Function (CDF) receives charging events from the CTF via the Rf reference point. It then uses the information contained in the charging events to construct CDRs. This procedure is characterised by the following conditions: - CDRs may be constructed from single charging events, i.e. a 1:1 relation between event and CDR. - CDRs may be constructed from a set of several charging events, i.e. a n:1 relation between event and CDR. - Each charging event is used for exactly one CDR, i.e. a 1:n relation between event and CDR (with n>1) is not possible. - Multiple charging events that are used to create a single CDR may not necessarily be of the same type. - There is no requirement or assumption of any synchronisation between the reception of the charging event(s) and the creation of the resulting CDR. However, the CDF shall be capable of receiving and processing charging events and generating the resulting CDR in near real-time. - The relationship between CDF and CTF may be 1:1 (integrated CDF) or 1:n (separated CDF) (refer to clause 4.5 for possible physical configurations of the logical charging functions). This includes the possibility of NEs of different types feeding charging events into the same CDF. - All charging events used to build a CDR must originate from the same NE, i.e. there is no cross-NE or cross-NE-type correlation of charging events in the CDF. The results of the CDF tasks are CDRs with a well-defined content and format. The content and format of these CDRs are specified per domain / subsystem / service in the related middle tier TS (e.g. TS 32.250[ Telecommunication management; Charging management; Circuit Switched (CS) domain charging ]  [10] for the CS domain and TS 32.251[ Telecommunication management;Charging management;Packet Switched (PS) domain charging ]  [11] for the PS domain, etc,).