Analysis and Design of IN Services by Role Modeling

This presentation addresses service analysis and design in a future intelligent broadband network. The presentation is based on work that has been carried out in Eurescorn project 103 (PI03). In P103 Service Creation and Composition Guidelines have been developed. The guidelines define an object oriented method for the analysis and design of future IN services. The method is based on role modelling and on the use of Message Sequence Charts (MSC) and SDL-92 to specify behaviour. A role model is a specification of one elementary task (concern) of a service. Several role models can be combined to arrive at object types for the complete service. We call this combination synthesis. The guidelines have been used to analyse a Video Conference Manager. The conference manager has the overall control of a multiparty video conference. Some of the role models for the conference manager are discussed, and a simple example is presented to show how the role models can be combined in order to derive object types for the conference manager. Our results indicate that role modelling is a natural and efficient way to cope with service development. Role models are also well suited to identify similar problems in different services at an early stage of analysis. Therefore role models provide a good basis for reuse. In P103 our aim is to define reusable service constituents by following the guidelines. The principles of role modelling were originally presented by professor Trygve Reenskaug et al. (University of Oslo). The authors would also like to thank Bengt Jensen, Norwegian Telecom Research, and Carla Capellman, Deutsche Bundespost Telekom for their contribution to the results in P103.