ICrafter: A Service Framework for Ubiquitous Computing Environments Shankar Ponnekanti, Brian Lee, Armando Fox, Pat Hanrahan, Terry Winograd (Stanford Univ.)

Outline What Why How Example Model and Terminology Challenges Contributions How Architecture Techniques

Example

Example (Contd.)

Model and Terminology Workspace: A physically confined environment intended for collaboration

Model and Terminology (contd.) Service A h/w or s/w resource Provides a useful function to end-users Example: Light, projector, browser, ppt Appliance Facility used for interaction with services Example: Laptop, PDA SUIML Swing UI Markup Language

Outline What? Why? Challenges Contributions How?

Appliance Heterogeneity Must accommodate a variety of UI languages/ modalities.

Workspace Heterogeneity UI’s must reflect workspace configuration

Aggregation May seem individual UI’s can be combined. However ….

UI(S1+S2) != UI(S1)+UI(S2) Good for individual operations Clumsy for compound operation: snap-and-display

UI(S1+S2) != UI(S1) + UI(S2) Transfer = snap and display in one click

Where We Stand Suppose n services, m appliances and w workspaces O( F(n) × m × w ) UI’s F(n) is some combinatorial function of n Existing ad-hoc interaction systems: Jini, UPnP, Hodes et al (Mobicom97, USITS99), Roman et al (WMCSA00) Mostly focus on appliance heterogeneity

Results Offload UI selection to third-party (i.e, non-service, non-appliance) Generalize existing approaches to appliance heterogeneity Frameworks for handling workspace heterogeneity and Techniques for aggregation

Outline What? Why? How? Architecture Techniques

Architecture Interface Manager Network Service Appliance

Interface Manager Generator Selector Generator Repository RequestUI(appl, target services) Generator Processor ReturnUI User Appliance

Example Generator <form action=… > { S1 = lookup_cmx (“Proj1”, “src1”) S2 = lookup_cmx(“Proj1”, “src2”) } <P> Select one of the following: <input type=radio .. >{print $S1} <input type=radio .. >{print $S2} …. </form> <form action=…> <P> Select one of the following: <input type=radio>Left screen <input type=radio>Right screen …. <//form>

Generators: Handling Appliance Heterogeneity Existing work: two extremes of quality/effort tradeoff UI’s for each service for every appliance (Jini, UPnP, Hodes et al [Mobicom97] Generic appliance-independent service descriptions (Roman et al [WMCSA00]

Specialization Hierarchy Services Appliances HTML SUIML FunkyML HPPrinter More Effort Better Quality Printer DataConsumerDevice Device

Appliance Specificity Generator Spectrum HPPrinterService HTML Generator HPPrinterService SUIML Generator PrinterService HTML Generator PrinterService SUIML Generator DataConsumerDevice HTML Generator DataConsumerDevice SUIML Generator Fully Generic HTML Generator Fully Generic SUIML Generator Service Specificity Appliance Specificity

Generators: Workspace Heterogeneity All workspace configuration stored in a centralized "context memory" (Winograd, HCI ’01) Generators access configuration information using fixed APIs lookup_cmx(service, configuration property) Advantages of centralized configuration easier to administer flexible, powerful queries

Examples lookup_cmx(light, “location”) lookup_cmx(projector, “source1”)

Generators: Handling Aggregation Generators for multiple services Eg. {Camera, Display}, {Camera, Display, Display} Generators for service patterns Eg. {Camera, Display+}, {Projector* } Generators for service interface patterns Eg. {DataProducer, DataDisplayer+}

Simplified Example Request for {Camera, Display} Matches Camera generator, Display generator, and {DataProducer, DataDisplayer} generator

Simplified Example Aggregated using panels

Outline What? Why? How?

Bootstrapping

Future Work Authentication and synchronization Aggregation: more intelligent generator set selection: Eg. Eliminate a {DataProducer, DataDisplayer} generator if a {Camera, Display} generator exists

Interactive Workspaces Project Info Some software already available Major release (including ICrafter) due this month For software and other info: http://iwork.stanford.edu/