Software Architecture Framework for Ubiquitous Computing Divya ChanneGowda Athrey Joshi

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

Introduction Ubiquitous computing Requirements Ubiquitous computing Requirements Interoperability: Ability of software to understand the exchanged information Interoperability: Ability of software to understand the exchanged information Heterogeneity: Integrate heterogeneous network technologies, Operating Systems, Programming Languages, devices and users 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 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 Adaptability: Software services must adapt to different kinds of terminals and networks

Introduction A middleware layer primarily hides the underlying complexity of the environment 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 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 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 HOMEROS – Middleware – layered architecture addressing the challenges

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

HOMEROS ARCHITECTURE

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

Components (contd.) Component Repository 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 System Support Layer Context Manager 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 QoS-Adaptation  collects various device monitoring information from resource manager  provides QoS information to the configuration manager.

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

Illustration Ubiquitous Printing Service

Ubiquitous Printing Service Operation

Operational mechanism 1. User pushes the send picture button, the PDA realizes a new data 2. CM analyses the data and data is sent to QA 3. Authenticates the user and returns the result to CM 4. CM forwards the data to EM 5. EM manages printing factory (Job, Schedule Process, and Event Queue), 6. Data is sent to CCM 7. CCM sends it to CR for querying whether component exists or not

Operational mechanism(Alternate Flow) 8. CR returns availability of the resource to CCM 9. Sends the picture data (user position, pixel, resolution, and so on), property, and existence of component to Discovery Server 10. Sends the print requests to photo shops 11. Photo shop server acknowledges the request along with the price and location map to Discovery Server 12. Discovery server forwards the acknowledgement and the result to the Middleware ( CM ) 13. 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

Operational mechanism(Alternate Flow) 13. If printing component not discovered in the step 8. The request is fowarded to CR 14. CR sends request to SM and also to CFM 15. SM returns certificate of authentication. And CFM sends the configuration details to RM. 16. RM allocates the resource and sends it back to CFM 17. CFM sends the data to QA 18. QA decides on the quality and forwards it to the user

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

References 1. Seung Wok Han, Yeo Bong Yoon, and Hee Yong Youn, “A New Middleware Architecture for Ubiquitous Computing Environment”, second IEEE WSTFEUS, Eila Niemelä, Juhani Latvakoski, “Survey of Requirements and Solutions of Ubiquitous Software “, Proceedings of the 3 rd International Conference on Mobile Ubiquitous Multimedia, 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 , 1995

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