An IN-Based Approach to the Design of Interactive Multimedia Services Over Broadband Networks: The VoD Example

The evolving Interactive M ultimedia (IM M) services require the development of ¯ exible and easily adaptable design tools that can interoperate with the underlyin g broadban d communication network. In this paper, we adopt a design philosophy based on the Intelligen t Network (IN) concept. The main advantage of this approach is the transparency of the service-speci® c features to the underlying signaling system. Hence, a fast introduction of demanding services becomes possible even if the signaling of the network i s not sophisticated enough to fully cover the requiremen ts of IM M services. The standard International Telecommun ication Union (ITU) Service Independent Block (SIB)-based methodology is used as a basis and further extended, where necessary, to cover new requirements, not originally predicted for Narrowban d-Integrate d Services Digital Network (N-ISDN), but arising from IM M services. The paper further proceeds with the development of an Interactive Multimed ia O bject Class Library (IM OCL) which adopts a high-level object-oriented approach that supports an easy evolution of IN-based service design towards implementation. The IMOCL is kept generic to the most possible extent aiming to provide a common framework for the design of a wide variety of IM M services using the IN concept. The IMOCL encompasses service managemen t functionality enabling the designer and provider of an IN service to manage the newly introduced service. Both ITU SIB-based and IM OCL methodologies, together with the standard Speci® cation and Descriptio n Language (SDL) technique are demonstrated in the design of selected parts of a typical Video on Demand (VoD) service.