A QoS-aware service selection algorithm for multimedia service overlay networks

Multimedia applications are becoming more and more popular on today´s Internet. Given the enormous development costs and less flexibility, traditional monolithic based approaches are not suitable for building large-scale multimedia systems. By composing of distributed, autonomous services dynamically to provide more complex tasks, service composition provides an attractive way for building large-scale Internet applications. So, multimedia service composition provides a viable solution to large-scale complex multimedia systems. One of the challenging issues of multimedia service composition is how to find service paths to route the data flows through while meeting the applications´ resource requirements and specific QoS constraints. However, QoS-aware service routing problem is typically NP-hard. In this paper, we propose a heuristic algorithm named greedy-EF to solve this problem more effectively. More specially, greedy-EF uses an aggregate function to evaluate the QoS conditions for each service instance, and a hop-by-hop service selection approach to explore the proper service path. Simulations show that greedy-EF algorithm can achieve desired QoS assurances as well as load balancing in multimedia service overlay networks.