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

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

3. Example

4. Example (Contd.)

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

6. 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

7. Outline
What?
Why?
Challenges
Contributions
How?

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

9. Workspace Heterogeneity
UI’s must reflect workspace configuration

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

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

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

13. 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

14. 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

15. Outline
What?
Why?
How?
Architecture
Techniques

16. Architecture
Interface Manager
Network
Service
Appliance

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

18. 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>

19. 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]

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

21. 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

22. 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

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

24. 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+}

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

26. Simplified Example
Aggregated using panels

27. Outline
What?
Why?
How?

28. Bootstrapping

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

30. Interactive Workspaces Project Info
Some software already available
Major release (including ICrafter) due this month
For software and other info: