4.2 CS domain offline charging architecture

32.2503GPPCharging managementCircuit Switched (CS) domain chargingRelease 17Telecommunication managementTS

Figure 4.2.1 illustrates the 3^rd Generation charging logical architecture, which is subdivided by the two transmission planes, the Circuit Switched (CS) domain and the Packet Switched (PS) domain. The entities of the CS domain are encircled by the related box on the left hand side of the figure.

Figure 4.2.1 : 3G charging logical architecture

The components grouped in the grey boxes constitute what was referred to as the "MSC" prior to 3GPP Rel-4. The boxes which show red lines are those that are relevant for CS domain charging. While not shown explicitly in figure 4.2.1, the VLR may also generate CDRs (cf. figure 4.1.1 for the relationship between VLR and MSC server). In addition, the gsmSCF may also produce CDRs, however, these are not subject to 3GPP standardization.

Figure 4.2.2 specifies the mapping of the 3GPP common charging architecture, as laid down in 3GPP TS 32.240 [1], onto the CS domain.

As depicted in figure 4.2.2, all charging functions (CTF, CDF and CGF) reside within each CS Network Element (i.e. the MSC server, the VLR, and the HLR). Thus, the CS nodes are connected directly to the Billing Domain via the Bc reference point. This implies that there exists no separate CDF and CGF for the CS domain, and no corresponding open interfaces between any such functions, within the 3GPP standards.

However, vendors may choose to implement separate CDF and CGF for the CS domain. In that case, the interfaces between these functions should comply with the definition of the Rf and Ga reference points (TS 32.299 [50] and TS 32.295 [54], respectively) as much as possible.

BD

CS-NE

B_c

CDF/CGF

CTF/CDF/CGF

Figure 4.2.2: CS offline charging architecture