4th International workshop on middleware for pervasive and ad-hoc computing (MPAC 2006)

Building on the success of the 2003, 2004 and 2005 workshops, this year the workshop sought to further develop the roadmap for research on the essential middleware abstractions and infrastructures for ad-hoc and pervasive computing in general, and sensor-based services in particular.Over the past decade, large-scale ad-hoc and pervasive computing environments have grabbed the attention of the research community as evidenced by the large number of research and development projects in the area. However, despite considerable progress, the promise of pervasive computing still remains elusive. The diversity in currently available devices, networking infrastructure and information content has complicated research efforts, forcing many projects to focus only on point-examples of this technology.This workshop is premised on our belief that underpinning middleware mechanisms are central in weaving together the multitude of sensing, computing, communication and information technologies. In this respect, middleware for pervasive computing and ad-hoc networking provides two core research areas. In particular, pervasive computing middleware will allow you to take advantage of the resources in your environment to tailor your services and applications for seamless access and unrestricted mobility. Ad-hoc networking middleware will permit the formation of ad-hoc communities for new applications. However, such pervasive and ad-hoc environments pose some serious challenges to existing middleware technologies and approaches. In recent years research efforts have started to focus on addressing the middleware challenges posed by pervasive and ad-hoc computing environments, with relevant papers appearing in the main middleware conference program. Despite these efforts, proposed approaches are far from being the definitive answer to the issues raised, as there are still significant areas in need of further exploration. In this process the MPAC workshop continues to play an important role as a venue for discussing novel middleware abstractions and infrastructures.This year the workshop received a high number of quality submissions. Ten papers out of the twenty four originally submitted were chosen for these proceedings. These papers cover a broad range of issues including service discovery, trust and connectivity management in ad-hoc environments; and modeling, architectural issues, and context information dissemination in pervasive computing environments. More specifically, Lee at al. propose a scheme for the efficient propagation of service information in ad-hoc environments, while Flore-Cortés et al. develop a framework supporting multi-protocol service discovery. In the area of ad-hoc computing systems, Siegemund et al. propose a system that manages connectivity across different networks using visual tags displayed on the mobile devices, while Repantis and Kalogeraki propose a reputation system for managing trust in ad-hoc, peer-to-peer networks. In the area of pervasive computing, Norbisrath et al. introduce a configuration model for the development of e-Home systems, while Williamson et al. and Shi et al. focusing on the issues of management and dissemination of context information, the former proposing an epidemic gossip-based platform for information dissemination, while the latter exploring the use negotiation between context providers to satisfy context information requirements. In the theme of architectural issue in pervasive computing, Malek et al. describe a middleware infrastructure that directly supports architectural abstractions for pervasive systems development, Bunde-Pedersen et al. propose an adaptive hybrid architecture that combines the advantages of centralized and peer-to-peer designs, while Ahmed et al. propose a lightweight component management infrastructure that supports flexibility and reconfigurability in ubiquitous computing environments