How is the Customer charged for Roaming Usage

What is HLR?

As mentioned earlier, HLR is an acronym for Home Location Register – the functional unit responsible for managing mobile subscribers. Basically, HLR consists of subscriber information and part of the mobile information that allow incoming calls to be routed to the mobile subscriber. The HLR stores the IMSI, MSISDN number, VLR address, and subscriber data on supplementary services. In short it is the main database of permanent subscriber information for a mobile network. The HLR is an integral component of code division multiple access (CDMA), time division multiple access (TDMA), and Global System for Mobile communications (GMS) networks. Working with other call processing functions, the HLR provides the MSCs with information about the subscriber level, location and all services available to that user/

 

What is VLR?

VLR stands for Visitors' Location Register. Functioning in much the same way as the HLR, it is the local database maintained by the Cellular Service provider to identify the roamers or visitors on the network.

The HLR and VLR are the key databases to the GSM system.

 

 

How is the customer charged for Roaming Usage?

Now as the VLR has found the customer to be authentic, the customer is allowed to use cellular services. The MSC of the visited network generated a CDR for each call made or received by the customer while roaming. The CDR in turn goes to the Billing system via Mediation. We will understand what Mediation is a little later. The billing system in turn decodes the CDR, applies Business logic and finally rates the CDR or the call. The final output of the Billing system could be a TAP file and customer bill. The below diagram will help u understand the scenario more clearly.

Fig please

OSS/BSS put together: fig please