The feature and service interaction problem in telecommunications systems: a survey

Today's telecommunication systems are enhanced by a large and steadily growing number of supplementary services, each of which consists of a set of service features. A situation where a combination of these services behaves differently than expected from the single services' behaviors, is called service interaction. This interaction problem is considered as a major obstacle to the introduction of new services into telecommunications networks. We present a survey of the work carried out in this field during the last decade (1988-98). After a brief review of classification criteria that exist for feature interactions so far, we use a perspective called the emergence level view. This perspective pays respect to the fact that the sources for interactions can be of many different kinds, e.g., requirement conflicts or resource contentions. It is used to rationalize the impossibility of coping with the problem with one single approach. We also present a framework of four different criteria in order to classify the approaches dealing with the problem. The general kind of approach taken, a refinement of the well known detection, resolution, and prevention categories, serves as the main classification criterion. It is complemented by the method used, the stage during the feature lifecycle where an approach applies, and the system (network) context. The major results of the different approaches are then presented briefly using this classification framework. We finally draw some conclusions on the applicability of this framework and on possible directions of further research in this field.