Secure Systems Research Group - FAU Context Architectures Using Web Services PhD Candidate: Alvaro E. Escobar Advisors: Dr. Maria Petrie Dr. Eduardo Fernandez Department of Computer Science and Engineering Florida Atlantic University, Boca Raton FL. 07/27/2007

Secure Systems Research Group - FAU Agenda Review the following papers: [Fou06] D Fournier, S B Mokhtar, N Georgantas,VIssarny. “Towards Ad-hoc Contextual Services for Pervasive Computing”. Proceedings of the 1st workshop on Middleware for Service Oriented Computing (MW4SOC 2006) Melbourne, Australia [Bar05] J E Bardram. “The Java Context Awareness Framework (JCAF) – A Service Infrastructure and Programming Framework for Context-Aware Applications”. Centre for Pervasive Computing, Department of Computer Science, University of Aarhus. Denmark. [Dom07] KM Dombroviak, R Ramnath. “A taxonomy of mobile and pervasive applications ”. Proceedings of the 2007 ACM symposium on Applied computing. Seoul, Korea. [Bha05] R Bhatti, E Bertino, A Ghafoor. “A Trust-Based Context- Aware Access Control Model for Web-Services”. Distributed and Parallel Databases, Springer.

Secure Systems Research Group - FAU Towards Ad-hoc Contextual Services for Pervasive Computing [Fou06] Main Idea: –How to incorporate context-aware concepts into SOA to enable context-aware services for pervasive computing. Managing Context Information: –managed by centralized system and devices are consumers of context in a specific physical environment (pervasive spaces). –managed by devices so they have access to context in any environment.

Secure Systems Research Group - FAU Towards Ad-hoc Contextual Services for Pervasive Computing [Fou06] Taxonomy of Context Information: –User Domain –System Domain –Environment (physical) Domain Context Representation: –Key-Value models –Markup models –Graphical models –Object-Oriented models –Logic models –Ontologies

Secure Systems Research Group - FAU Towards Ad-hoc Contextual Services for Pervasive Computing [Fou06] User Domain Context: –Provide knowledge to enable applications adapt to the profile of their users. Subjective: Includes user’s personality and psychology. –User mood and feelings (fear, anger, sad…) Objective: Includes user’s personal information. –Personal information (name, last name, birth date…) –Physiology information (height, weight, health…) –Agenda information (user activities over time)

Secure Systems Research Group - FAU Towards Ad-hoc Contextual Services for Pervasive Computing [Fou06] System Domain Context: –Describes digital, software and hardware resources available to users. –Processing power –Hardware components –Network interfaces –Storage –Software components

Secure Systems Research Group - FAU Towards Ad-hoc Contextual Services for Pervasive Computing [Fou06] Environmental Domain Context: –Deals with the description of location and of conditions of the physical environment. –Physical geography (GPS coor, room, building….) –Physical conditions (windy, sunny, rainy…) –Chronology (time, time zone, time of the day)

Secure Systems Research Group - FAU Towards Ad-hoc Contextual Services for Pervasive Computing [Fou06] Context Representation : –Key-Value models: use a set of attributes and their associated values. –Markup models: structure context into a hierarchy using tags. –Graphical models: express relationships between context entities. –Object-Oriented models: structure context into object classes and their implicit relationships. –Logic models: express context in terms of facts and rules. –Ontologies: combination of logic models and O-O models they structure context into object classes and their explicit relationships.

Secure Systems Research Group - FAU Towards Ad-hoc Contextual Services for Pervasive Computing [Fou06] Context Management : –Initially application-specific context managers (limited re-use; built for app-specific context). Location-aware systems like Active Badge and Cyberguide. –Then dedicated Context Frameworks allowed more general (re-usable) context managers. Context Toolkit (Dey), Contextors (Coutaz) JCAF (Bardram)

Secure Systems Research Group - FAU Towards Ad-hoc Contextual Services for Pervasive Computing [Fou06] Context Management (continue): –Lately is the Server-Oriented approach to context managers ( deployment of context servers within the network). SOCAM (Service-Oriented Context Aware Middleware) CoBra (Context Broker Architecture) –More recently the P2P architecture of context managers (devices responsible for managing subset of context). AWARENESS project, where mobile and desktop devices acquire, interpret and exchange context even in the absence of a context server.

Secure Systems Research Group - FAU Towards Ad-hoc Contextual Services for Pervasive Computing [Fou06] Context Sources

Secure Systems Research Group - FAU Towards Ad-hoc Contextual Services for Pervasive Computing [Fou06] Context Consumption

Secure Systems Research Group - FAU Towards Ad-hoc Contextual Services for Pervasive Computing [Fou06] Context-aware Services

Secure Systems Research Group - FAU Conclusions Context is a fundamental concept in mobile systems. Service-Oriented computing has emerged as a promising paradigm for pervasive computing. One challenge is making services contextual, so that the pervasive computing environment gets knowledge about the context and the services adapt their behavior accordingly. Contextual Services may be composed in an ad hoc way.

Secure Systems Research Group - FAU Towards Ad-hoc Contextual Services for Pervasive Computing References: –[Bel03] P. Bellavista, A. Corradi, R. Montanari, C. Stefanelli, “Context-Aware Middleware for Resource Management in the Wireless Internet”, IEEE Transactions on Software Engineering. Vol. 29, No. 12, December Page –[Bra01] T. Bray. What is RDF? –January 24, 2001 –[Cha04] T. Chaari, F.Laforest, A. Celentano. “Design of Context-Aware Applications. Based on Web Services”. LIRIS. Dipartimento di Informatica. INSA Lyon, France –[Che03] H. Chen, T. Finin and A. Joshi. “An Ontology for Context-Aware Pervasive Computing Environments”. IJCAI Workshop on Ontologies and Distributed Systems, IJCAI 2003, Acapulco, Mexico, –[Cor04] A. Corradi, R. Montanari, D. Tibaldi, “Context-Based Access Control Management in Ubiquitous Environments”, Network Computing and Applications, Proceedings of the Third IEEE International Symposium on (NCA'04), August 30 - September 01, 2004, Boston, MA. –[Dey01] A. Dey, G. Abowd, D. Salber, “A Conceptual Framework and a Toolkit for Supporting the Rapid Prototyping of Context-Aware Applications” - Human-Computer Interaction, Lawrence Earlbaum –[Fer07] E. B. Fernandez, A. E. Escobar, M. Larrondo-Petrie. “Contexts and Context-Based Access Control”. The Third International Conference on Wireless and Mobile Communications, ICWCF’07, March Guadeloupe, French Caribbean. –[Fer05] E.B. Fernandez, T. Sorgente, N. Delessy, and M.M.Larrondo-Petrie, "A survey of web services security", Technical report to DISA (Defense Information Systems Agency), grant # ?????, 2005 –[Fer04] E.B. Fernandez, "Web services security: An overview of standards and industrial practice", 2004 –[Gu04] T. Gu, X.H. Wang, H.K. Pung, D.Q. Zhang. “An Ontology-based Context Model in Intelligent Environments”, Proceedings of Communication Networks and Distributed Systems, –[Hel02] A. Held, S. Buchholz, A. Schill, "Modeling of Context Information for Pervasive Computing Applications", In Proceedings of the 6th World Multiconference on Systemics, Cybernetics and Informatics (SCI), Orlando, FL, July –[Rae05]M. Raento, A. Oulasvirta, R. Petit, H. Toivonen. “ContextPhone: A Prototyping Platform for Context-Aware Mobile Applications”. IEEE Pervasive Computing, –[Sil05] J. Siljee, S. Vintges, J. Nijhuis. “A Context Architecture for Service-Centric Systems”. Context Modelling and Management in Ambient- Aware Pervasive Environments. LoCA 2005, Oberpfaffenhofen, Germany, May 12-13, –[W3C04]

Secure Systems Research Group - FAU Agenda Review the following papers: [Fou06] D Fournier, S B Mokhtar, N Georgantas,VIssarny. “Towards Ad-hoc Contextual Services for Pervasive Computing”. Proceedings of the 1st workshop on Middleware for Service Oriented Computing (MW4SOC 2006) Melbourne, Australia [Bar07] J E Bardram. “The Java Context Awareness Framework (JCAF) – A Service Infrastructure and Programming Framework for Context-Aware Applications”. Centre for Pervasive Computing, Department of Computer Science, University of Aarhus. Denmark. [Dom07] KM Dombroviak, R Ramnath. “A taxonomy of mobile and pervasive applications ”. Proceedings of the 2007 ACM symposium on Applied computing. Seoul, Korea.

Secure Systems Research Group - FAU Future Work Develop a service oriented context-aware middleware that will enrich the JCAF. –Updating our Context-aware model to incorporate Web Services. –Simulate the many context and location-aware scenarios through that model. –Build sequence diagrams for some Use Cases to validate our model. Paper submission for: – UbiComp’07 - 9th International Conference on Ubiquitous Computing, September 2007, Innsbruck, Austria. (June deadline) – ACM Symposium on Applied Computing 2008, Special Track on Ubiquitous Computing:Ubiquitous and Pervasive eCommerce and eBusiness. March , 2008, Fortaleza, Brazil. (Sept deadline) –MobiSys’08 - The 6th International Conference on Mobile Systems. TBA –MobiHoc’08 - The 9th ACM International Symposium on Mobile Ad Hoc Networking and Computing. May 26-30, 2008, Hong Kong (Nov/22 deadline)