HSS Front-End implementation for a large scale common HLR/HSS

Abstract: With rapid growth in the use of telecommunication services, subscribers enjoy value-added services via different telecommunication technologies. The telecommunication companies need to get a single view of the subscriber data in order to profile them (for example:profitable subscribers) and reduce operational costs by the virtue of maintaining common subscriber data. A Home Location Register (HLR) in Global System for Mobile Communication (GSM) domain and Home Subscriber Server (HSS) in IP Multimedia  Subsystem (IMS) domain store subscriber data. A subscriber may use both GSM and IMS services. The 3rd Generation Partnership Project (3GPP) has specified separate standard specifications for HLR and for HSS. As a result, in many cases there is duplication of subscriber data in both of them. Minimizing duplication in subscriber data can be accomplished by developing a common HLR/HSS. This would result in providing single view of the subscriber data in the GSM and IMS services. This thesis work investigates the possibility to implement a common HLR/HSS product by adding a HSS Front-end (FE) server and an IMS subscriber database to an already existing HLR implementation consisting of a HLR FE server and a GSM subscriber database. The FE HSS/HLR  prototype  was designed and developed using Erlang /Open Telecom Platform (OTP). The prototype  developed is capable of handling Diameter queries from the Application Server (AS) and Call Control State Function (CSCF) in the IMS domain and provides HLR database access in the GSM domain. Performance analysis of the third-party tools, components and the prototype  was carried out to evaluate real-time characteristics.