ICrafter: A Service Framework for Ubiquitous Computing Environments

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ICrafter A Service Framework for Ubiquitous
Computing Environments

• Shankar Ponnekanti, Brian Lee, Armando Fox, Pat
  Hanrahan, Terry Winograd (Stanford Univ.)

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Outline

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

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Example
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Example (Contd.)
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Model and Terminology

• Workspace A physically confined environment
  intended for collaboration

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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

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Outline

• What?
• Why?
• Challenges
• Contributions
• How?

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Appliance Heterogeneity

• Must accommodate a variety of UI languages/
  modalities.

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Workspace Heterogeneity

• UIs must reflect workspace configuration

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Aggregation

• May seem individual UIs can be combined. However
  .

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UI(S1S2) ! UI(S1)UI(S2)

• Good for individual operations
• Clumsy for compound operation snap-and-display

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UI(S1S2) ! UI(S1) UI(S2)

• Transfer snap and display in one click

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Where We Stand

• Suppose n services, m appliances and w workspaces
• O( F(n) m w ) UIs
• 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

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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

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Outline

• What?
• Why?
• How?
• Architecture
• Techniques

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Architecture
Interface Manager
Network
Service
Appliance
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Interface Manager
User Appliance
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Example Generator

• ltform action gt
• S1 lookup_cmx (Proj1, src1)
• S2 lookup_cmx(Proj1, src2)
• ltPgt Select one of the following
• ltinput typeradio .. gtprint S1
• ltinput typeradio .. gtprint S2
• .
• lt/formgt

• ltform actiongt
• ltPgt Select one of the following
• ltinput typeradiogtLeft screen
• ltinput typeradiogtRight screen
• .
• lt//formgt

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Generators Handling Appliance Heterogeneity

• Existing work two extremes of quality/effort
  tradeoff
• UIs for each service for every appliance (Jini,
  UPnP, Hodes et al Mobicom97
• Generic appliance-independent service
  descriptions (Roman et al WMCSA00

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Specialization Hierarchy
Services
HPPrinter
More Effort Better Quality
Printer
DataConsumerDevice
Device
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Generator Spectrum
Service Specificity
Appliance Specificity
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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

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

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Simplified Example

• Request for Camera, Display
• Matches Camera generator, Display generator, and
  DataProducer, DataDisplayer generator

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Simplified Example

• Aggregated using panels

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Outline

• What?
• Why?
• How?

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Bootstrapping
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Future Work

• Authentication and synchronization
• Aggregation more intelligent generator set
  selection
• Eg. Eliminate a DataProducer, DataDisplayer
  generator if a Camera, Display generator exists

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Interactive Workspaces Project Info

• Some software already available
• Major release (including ICrafter) due this month
• For software and other info http//iwork.stanford
  .edu/