Secure Systems Research Group - FAU Context Architectures Using Web Services Candidate: Alvaro E. Escobar Advisors: Dr. Maria Petrie Dr. Eduardo Fernandez Department of Computer Science and Engineering Florida Atlantic University, Boca Raton FL. 01/04/2007

Secure Systems Research Group - FAU Agenda Review the following papers: [Cha04] T. Chaari, F.Laforest, A. Celentano. “Design of Context-Aware Applications Based on Web Services”. LIRIS. Dipartimento di Informatica. INSA Lyon, France [Maa06] Z. Maamar, D.Benslimane, N. Narendra. “What can Context do for Web Services?”. Communications of the ACM, December 2006/Vol. 49, No. 12. Review our Context-aware Model Context Architecture Using Web Services

Secure Systems Research Group - FAU Design of Context-Aware Applications Based on Web Services [Cha04] Context: –A way to adapt the behavior and the interface of an application, to the user situation and equipment. Adaptation vs Context-awareness: –Adaptation: Capability to provide different versions/presentations of a service in order to suite the needs of the user. –Context-awareness: Capability of perceiving the user situation and of adapting the system behavior, as a consequence.

Secure Systems Research Group - FAU Design of Context-Aware Applications Based on Web Services [Cha04] Steps to Context-awareness: [Dey01] 1.Capture low level contextual data from sensors. 2.Build high level contextual information by interpreting data captured on step one. 3.Carry interpreted information to the application and provide possible ways on how it can adapt to context changes.

Secure Systems Research Group - FAU Design of Context-Aware Applications Based on Web Services [Cha04] Context representations: –Simple set of Attribute/Value pairs. [Bel03,Cor04,Dey01,Fer07] –Use of RDF (Resource Description Framework). [Bra01, Hel02] –As Ontologies. [Che03,Gu04]

Secure Systems Research Group - FAU Design of Context-Aware Applications Based on Web Services [Cha04] How the application can adapt to context changes. Four approaches: –Conceptual Frameworks: Focus on the architectural aspect of context-aware systems. [Dey01] –Service Platforms: Focus on providing pertinent services to a user, depending on context. –Appliance Environments: Focus on giving solutions to the heterogeneity problem by providing interoperability techniques and frameworks. –Computing Environments: Focus on designing the physical and logical infrastructure to hold ubiquitous systems.

Secure Systems Research Group - FAU Design of Context-Aware Applications Based on Web Services [Cha04] Development of context-aware apps. –Architecture supporting context-awareness at run-time. –design the application to be context-aware. Web Services –is widespread and “loosely coupling” approach to integration of applications. Adopt Web Services for context-aware application design.

Secure Systems Research Group - FAU Design of Context-Aware Applications Based on Web Services Service Oriented Architecture (SOA) [Cha04] 1.Context Capturing 2.Context Interpreting 3.Context Modeling 4.Context Dissemination 5.Context Adaptation Data flow (content) Visualization (UI) Application behavior (service)

Secure Systems Research Group - FAU Agenda Review the following papers: [Cha04] T. Chaari, F.Laforest, A. Celentano. “Design of Context-Aware Applications Based on Web Services”. LIRIS. Dipartimento di Informatica. INSA Lyon, France [Maa06] Z. Maamar, D.Benslimane, N. Narendra. “What can Context do for Web Services?”. Communications of the ACM, December 2006/Vol. 49, No. 12. Review our Context-aware Model Context Architecture Using Web Services

Secure Systems Research Group - FAU What can Context do for Web Services? [Maa06] Web Services (WS): –provide a language-neutral, loosely-coupled, and platform independent way for linking applications within organizations or enterprises across the Internet. –facilitates composite services (CWS): describes list of component WS involved. describes execution order of WS involved. describes corrective strategy in case of an exception.

Secure Systems Research Group - FAU What can Context do for Web Services? [Maa06] WS limitations: –processes the requests it receives without considering its execution status, before committing to another request. –lacks self-management to satisfy requirements of: Scalability: capacity of WS to interact with small or large community of WS without reducing its performance. Flexibility: capacity of WS to adapt behavior according to the situation in which it operates. Autonomy: capacity of WS to accept/reject/propose alternative demands of participation in CWS.

Secure Systems Research Group - FAU What can Context do for Web Services? [Maa06] A WS must assess its current capabilities, its ongoing commitments and its surrounding environment prior to binding to any CWS. Therefore WS must be context-aware: –Consider the following contextual aspects. Users: Stationary or mobile Expertise: Expert or novice Resources: Fixed or handheld Time: Morning or afternoon Location: Cafeteria or meeting room

Secure Systems Research Group - FAU What can Context do for Web Services? [Maa06] Applying context awareness on deploying WS. –Participation perspective: is about overseeing the multiple composition scenarios in which a WS participates. –Execution perspective: is about looking for the computing resources on which a WS operates and monitoring them. –Preference perspective: is about ensuring that user preferences are integrated into the specification of the CWS. Context supports WS in their decision-making process to whether accept or reject participation in a CWS.

Secure Systems Research Group - FAU What can Context do for Web Services? [Maa06] Applying context awareness on CWS semantics. –WS must agree on the meaning of the exchanged data. –Semantic conflicts must be resolved automatically using context. Languages OWL-S (Ontology Web Language for WS) and WSDL-S (WS Description Language) can handle data conflicts of type structure but cannot handle data conflicts of type value.

Secure Systems Research Group - FAU What can Context do for Web Services? [Maa06]

Secure Systems Research Group - FAU What can Context do for Web Services? [Maa06] Applying context awareness on WS conciliation. –W-Context: for context of WS (fine-grain content). –C-Context: for context of CWS (course-grain content).

Secure Systems Research Group - FAU Agenda Review the following papers: [Cha04] T. Chaari, F.Laforest, A. Celentano. “Design of Context-Aware Applications Based on Web Services”. LIRIS. Dipartimento di Informatica. INSA Lyon, France [Maa06] Z. Maamar, D.Benslimane, N. Narendra. “What can Context do for Web Services?”. Communications of the ACM, December 2006/Vol. 49, No. 12. Review our Context-aware Model Context Architecture Using Web Services

Secure Systems Research Group - FAU Context–Aware Model

Secure Systems Research Group - FAU Context–Aware Model

Secure Systems Research Group - FAU Context–Aware Model using Web Services

Secure Systems Research Group - FAU Agenda Review the following papers: [Cha04] T. Chaari, F.Laforest, A. Celentano. “Design of Context-Aware Applications Based on Web Services”. LIRIS. Dipartimento di Informatica. INSA Lyon, France [Maa06] Z. Maamar, D.Benslimane, N. Narendra. “What can Context do for Web Services?”. Communications of the ACM, December 2006/Vol. 49, No. 12. Review our Context-aware Model Context Architecture Using Web Services

Secure Systems Research Group - FAU Context Architecture Using Web Services

Secure Systems Research Group - FAU Conclusions Context is a fundamental concept in mobile systems. Different researchers use different variations of context. Web Services is the widespread approach to application integration. Integrated Web Services into our Context Model for easier application integration. Created a Context Architecture incorporating Web Services.

Secure Systems Research Group - FAU Future Work Simulate the many context and location-aware scenarios through our model. Build sequence diagrams for some Use Cases. The 4th International Conference on Ubiquitous Intelligence and Computing (UIC-07). Hong Kong, China, July 11-13, (01/15/2007) ICPS'07 : IEEE International Conference on Pervasive Services, July , 2007, Istanbul, Turkey (02/04/2007) ICWN'07- The 2007 International Conference on Wireless Networks. Monte Carlo Resort, Las Vegas, June 25-28, 2007 (02/20/2007) The Second International Conference on Pervasive Computing and Applications (ICPCA07) July 26-27, 2007, Birmingham, UK (02/28/2007) First International Conference on Autonomic Computing and Communication Systems, October 2007, Rome Italy (04/18/2007)

Secure Systems Research Group - FAU Context Architectures Using Web Services 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]