1. University of Jyväskylä 1 MODPA 26.08.2004WIM Workshop 15–17.09.2004 Components of Mobile Internet System Architecture from Design Patterns Point of View Oleksiy Mazhelis Information Technology Research Institute University of Jyväskylä, Finland E-mail: Oleksiy.Mazhelis@titu.jyu.fi

2. University of Jyväskylä 2 MODPA 26.08.2004WIM Workshop 15–17.09.2004 From applications to design patterns  Issues in application development include: –Complexity –Need to communicate design-related information –Need for organizational memory –Fast development of high-quality applications –Learning from successful designs  Design patterns offer: –Human-understandable abstractions of proven solutions –Common vocabulary –Aid for design documenting and reuse Application Component Quality attributes Quality attribute Quality attributes Design pattern Computational specification – decomposes the system into objects performing individual functions and interacting at well-defined interfaces  Some requirements are specific in mobile environments –Content adaptation –Independence from network access technology –Special design patterns may be needed To facilitate the identification of the design patterns applicable to a particular application, it may be reasonable first to decompose this application into components with desired quality attributes

3. University of Jyväskylä 3 MODPA 26.08.2004WIM Workshop 15–17.09.2004 Design patterns in mobile environment: an example  Utilizes MVC architecture pattern –Separates content from presentation, making portability to a new platform easier –Supports multiple, pluggable, synchronized views  New requirements important in a mobile environment –Simultaneous support for multiple UIs (depending on device capabilities) => changes in model would induce changes in all the UIs –Support for multiple browsers (HTML, WML)  As a result, changes in the MVC pattern may be needed so that new requirements could be met JSP Model 2 Browser (Controller) Servlet (View) JSP (Model) JavaBean Data Sources MVC Device-indep. UI model Device capabilities 1 2 3 4 5 UI generation

4. University of Jyväskylä 4 MODPA 26.08.2004WIM Workshop 15–17.09.2004 Generic components of applications Application Component Quality attributes Quality attribute Quality attributes Design pattern  We attempt to synthesize a tentative architectural model whose components can serve as generic building blocks for applications/services  This model will be employed in decomposing the applications into components so that the identification of suitable design patterns would be easier to perform

5. University of Jyväskylä 5 MODPA 26.08.2004WIM Workshop 15–17.09.2004 Enablers, common capabilities & functions  Based on: Nokia’s MITA, OMA’s OSE, Parlay’s OSA, and RM-ODP A technology intended for use in the development, deployment or operation of a Service… (OMA Dictionary) Basic mechanisms enabling the use of other enablers (OMA Inventory) Functions that can be reused by multiple enablers, providing common capabilities upon which other capabilities are built (OMA Dictionary)

6. University of Jyväskylä 6 MODPA 26.08.2004WIM Workshop 15–17.09.2004  Includes MITA’s layers  Includes (some of) potential end-points  User Interface & Domain Logic are parts of applications Tentative architectural model

7. University of Jyväskylä 7 MODPA 26.08.2004WIM Workshop 15–17.09.2004 Tentative architectural model (cont.)  End-points are not shown Common capabilities

8. University of Jyväskylä 8 MODPA 26.08.2004WIM Workshop 15–17.09.2004 Way to go  Testing the Model with Case Applications –Decomposing the applications into a set of components using the model –Identifying missing or misplaced components  Using the Model for Identifying Design Problems and Solutions –Based on requirements, defining quality attributes of components –Identifying design problems –Using architectural and design patterns, defining design solutions