Home Location Register (HLR) dedicated for Short Message Service (SMS)

Abstract: In telecommunication a Home Location Register (HLR) is used for keeping track of subscriber data for a multitude of services, including Circuit Switched (CS) calls, Short Message Service (SMS), and more. To support all functions, about 50 different complicated operations must be supported. This requires large sets of resources, both in time to implement and in capacity when in use. However, there are applications, for example vending machines, for which SMS is the only service needed to be supported. The goal of this thesis is to implement an HLR prototype, to explore the real-time characteristics of a subset of the HLR database operations required to support SMS only. The prototype  that we build and test, adheres to the standards specified by 3GPP. It is also much easier to configure and maintain than a conventional HLR, because it only supports one function. Most implementation was done using Erlang, a concurrent  soft real-time programming language widely used in telecoms.