Software Architecture Framework for Ubiquitous Computing

1. Software Architecture Framework for Ubiquitous Computing Divya ChanneGowda Athrey Joshi

2. Abstract • Ubiquitous computing permits users to compute “anywhere” and “any time” • Provides information services and applications through any device over different kinds of networks • Design challenges - Interoperability , Adaptability, Mobility, Heterogeneity • Approach - HOMEROS middleware architecture, Layered model • High flexibility by adopting a hybrid-network model and dynamically configurable reflective ORB • Illustration - Ubiquitous printing service scenario

3. Introduction • Ubiquitous computing Requirements • Interoperability: Ability of software to understand the exchanged information • Heterogeneity: Integrate heterogeneous network technologies, Operating Systems, Programming Languages, devices and users • Mobility: Users should be supported in such a way that they can move from one place or terminal to another and still get a personalized service • Adaptability: Software services must adapt to different kinds of terminals and networks

4. Introduction • A middleware layer primarily hides the underlying complexity of the environment • Insulates the applications from explicit protocol handling, disjoint memories, data replication, network faults, and parallelism • Masks the heterogeneity of computer architectures, operating systems, programming languages, and networking technologies to facilitate application programming and management • HOMEROS – Middleware – layered architecture addressing the challenges

5. HOMEROS • A hybrid-network model • Flexible - dynamically configurable ORB • Consists of three layers • Core Component Management Layer • Extended Component Service Layer • System Support Layer

6. HOMEROS ARCHITECTURE

7. Components • Core Component Management layer • Core Component Management • dynamic loading, unloading, components in the upper layers • remote component execution and management • Extended Component Service layer • Event Manager • distributes events • implements a decoupled communication model • Consists of a single entry point one or more event factories

8. Components (contd.) • Component Repository • Supports flexibility, adaptability • Stores information on all component entities in the middleware • Allows component manager to browse and retrieve entities • System Support Layer • Context Manager • provides proactive services using the user and resource information • The context manager offers basic services: context filtering, aggregation, evaluation, learning log • QoS-Adaptation • collects various device monitoring information from resource manager • provides QoS information to the configuration manager.

9. Components (contd.) • Configuration Manager • Automatic Installation and configuration of new components • provides a flexible infrastructure for dynamic software update and self-reconfigurable component module • Resource Manager • dynamic reallocation of resources • performs both self-inspection and self-adaptation • Security Manager • Registration and authentication

10. Illustration Ubiquitous Printing Service

11. Ubiquitous Printing Service Operation

12. Operational mechanism • User pushes the send picture button, the PDA realizes a new data • CM analyses the data and data is sent to QA • Authenticates the user and returns the result to CM • CM forwards the data to EM • EM manages printing factory (Job, Schedule Process, and Event Queue), • Data is sent to CCM • CCM sends it to CR for querying whether component exists or not

13. Operational mechanism(Alternate Flow) • CR returns availability of the resource to CCM • Sends the picture data (user position, pixel, resolution, and so on), property, and existence of component to Discovery Server • Sends the print requests to photo shops • Photo shop server acknowledges the request along with the price and location map to Discovery Server • Discovery server forwards the acknowledgement and the result to the Middleware ( CM ) • If printing component is discovered in step 8, CCM sends data to EM that commands the application to show a message on the screen of the PDA

14. Operational mechanism(Alternate Flow) • If printing component not discovered in the step 8. The request is fowarded to CR • CR sends request to SM and also to CFM • SM returns certificate of authentication. And CFM sends the configuration details to RM. • RM allocates the resource and sends it back to CFM • CFM sends the data to QA • QA decides on the quality and forwards it to the user

15. Conclusion • The above middleware architecture addresses the ubiquitous computing environment requirements like flexibility, interoperability successfully. • This architecture adopts a hybrid-network model to manage enormous resources, context, location data, and services.

16. References • Seung Wok Han, Yeo Bong Yoon, and Hee Yong Youn, “A New Middleware Architecture for Ubiquitous Computing Environment”, second IEEE WSTFEUS, 2004 • Eila Niemelä, Juhani Latvakoski, “Survey of Requirements and Solutions of Ubiquitous Software “, Proceedings of the 3rd International Conference on Mobile Ubiquitous Multimedia, 2004 • T.T. Drashansky, S. Weerawarana, A. Joshi, R.A. Weerasinghe, and E.N. Houstis, “Software Architecture of Ubiquitous Scientific Computing Environments for Mobile Platforms”, Tech. Report TR-95-032, 1995

17. Questions