Olle Pellijeff's Master Thesis

Master's Thesis
A Service Creation and Execution Environment
Based on the Intelligent Network Concept

[Top] [PA System] [IN Concept] [IN and PA] [Service] [Conclusion] [Report]

I performed my Master's Degree Thesis at Ericsson Radio Systems - Network Applications T/N. My supervisor was John-Olof Bauner ( John-Olof.Bauner@era-t.ericsson.se ), my examiner was Johan Bevemyr.

PA System

The department where I have conducted my thesis work have developed a prototype system for Personal Assistant (PA) services. The switch in the system is a PC with special hardware from Dialogic.

PA system structure

PA services provide the user with a personal telephone number and a range of services like voice-mail, reading email on a mobile telephone and screening.

IN Concept

The first phase of my work was to investigate the ITU Intelligent Network (IN) concepts.

IN conceptual model

The IN concept is structured into four planes.

The service plane is exclusively service-oriented. Services is described in terms of Service Features (SFs).

The global functional plane defines services in terms of Service Independent Building blocks (SIBs) that are reusable networkwide capabilities. The SIBs are chained together with global service logic to form scripts.

SIB concept

The distributed functional plane defines Functional Entities (FEs) and the information flow between them.

The physical plane shows how the FEs of the distributed functional plane can be implemented in physical products.

How to incorporate IN and PA

My goal is to use IN concepts to create a service creation and execution environment for the PA. The IN Application Lab at Ericsson Telecommunicatie BV in Holland has developed an IN simulator (contact Jan van der Meer etmjvdm@crosby.ericsson.se). I reuse most of their Service Creation Environment created by Erik Reitsma etmerei@crosby.etm.ericsson.se. With this tool you can design service scripts from SIBs in a graphical environment. The picture below shows how a script can look like at the screen.

An example of a service script

I implemented a Service Control Function (SCF) that is able to interprete service scripts. To be able to interprete my scripts I developed a destributed system with the help of Erlang's support for distribution. I also implemented a very simple Service Management Function (SMF) that provides monitoring and control of the system.

Structure of my PA IN concept

SIBs are implemented as Erlang functions. When executing a script, a script executer "threads" through the SIBs with the use of the meta command apply.

Execution of a script

The Service I Implemented

I choose to implement the part of the PA service that is triggered when someone calls the personal number of a PA user. This service is interesting in the aspect that the PA user is searched on several numbers in parallell. I wanted to investigate if the ITU-T IN concept of script was powerful enough to model this without to great an effort.

If you wish a scheme of the service click here.

Conclusion

It is hard to model a complex,concurrent and eventdriven service like the PA service with the ITU SIB/Script concept. The sequantial nature of the SIB/Script concept limits the flexibility of user interaction, which is undesirable. See the report for a more elaborate discussion.

The Thesis Report

There is a zipped postscript version of the thesis report (154K). Contact me if you wish the report in some other format.

If you are interested in the project please send me a mail.