Abstract. Distributed event routing has emerged as a key technology for achieving scalable information dissemination. In particular it has been used as preferential communication backbone within publish/subscribe communication system. Its aim is to reduce the network and computational overhead per event diffusion to a set (possibly large) of interested recipients. This paper introduces an unifying framework, namely a publish/subscribe architecture, that points out the functional decomposition between event-based routing layer, the overlay infrastructure layer and the network protocols layer. Hence the paper, firstly, surveys current algorithms for event based routing and possible overlay infrastructures in wired and mobile systems and, secondly, it discusses how and when single solutions at each level can be combined in the publish/subscribe architecture. Finally the paper positions existing publish/subscribe systems within the proposed architecture. 1

Content-based publish/subscribe is a powerful data dissemination paradigm that offers both scalability and flexibility. However, its nature of high expressiveness makes it difficult to analyze or predict the behavior of the system such as event delivery probability and end-to-end delivery delay, especially when deployed over unreliable, best-effort public networks. This paper proposes the analytical model that abstracts expressiveness nature of content-based publish/subscribe, along with uncertainty of underlying networks, in order to predict quality of service in terms of delivery probability and timeliness based on partial, imprecise statistical attributes of each component in the system. Furthermore, the paper leverages the proposed prediction algorithm to implements heuristic-based subscriber admission control algorithms to maximize system utility when the system cannot support all subscribers. The evaluation results yields good prediction accuracy and admission rates. I.