L. Baresi, C.-H. Chi, and J. Suzuki (Eds.): ICSOC-ServiceWave 2009, LNCS 5900, pp. 19–33, 2009. © Springer-Verlag Berlin Heidelberg 2009 Aspect Orientation for Composite Services in the Telecommunication Domain Jörg Niemöller, Roman Levenshteyn, Eugen Freiter, Konstantinos Vandikas, Raphaël Quinet, and Ioannis Fikouras Ericsson GmbH Ericsson Allee 1, 52134 Herzogenrath, Germany {joerg.niemoeller,roman.levensteyn}@ericsson.com, {eugen.freiter,konstantinos.vandikas}@ericsson.com, {raphael.quinet,ioannis.fikouras}@ericsson.com Abstract. Telecommunication network operators have specific requirements on services offered through their network, which are frequently independent of the core business logic of the service. As an example, these requirements ensure monitoring of user activities for charging purposes or allow controlling parame- ters that influence the quality of service. In order to satisfy these demands, ser- vices are typically tailor-made to support these supplementary features next to their core business logic. As a result, their implementation becomes tangled and specialized. This is identified as a major obstacle for efficient service composi- tion, because more specialized services are less suitable for being reused in dif- ferent contexts. This paper describes an approach to introduce concepts of aspect-oriented programming to service composition in order to keep the im- plementations of telecommunication-specific requirements separated from the core business function of a service. Keywords: AOP, IMS, Service Composition, Telecommunication. 1 Introduction Telecommunication network operators aim for a service infrastructure that allows a converged usage of heterogeneous services. They rely on cost-efficient and rapid design of new applications by re-use of already existing services. Another goal is differentiation form the competition by integrating telecommunication services with popular community services from the internet, because these services provide users with a new style of communication and social interaction. Service composition is a key technology for reaching the desired convergence within a heterogeneous service environment. This paper is based on an approach for service composition [1] that supports multiple service technologies to be used within a single composite service. Typically, operators from the telecommunication domain require support for spe- cific supplementary functions from all services provided through their network. These functions, for example, allow charging for service usage, collect statistics or help controlling the service quality.