Bin Wang, John Bodily and Sandeep K. S. Gupta Department of Computer Science and Engineering

1. Supporting Persistent Social Groups in Ubiquitous Computing Environments Using Context-Aware Ephemeral Group Management* Bin Wang, John Bodily and Sandeep K. S. Gupta Department of Computer Science and Engineering Ira A. Fulton School of Engineering Arizona State University *Supported by NSF

2. Imagine You are @ Percom05 in Hawaii! • Enhance the experience of conference attendees with pervasive computing group technology • Each attendee with multiple pervasive device • Automatic various social groups are formed to facilitate social interaction! • Percom05 • Surfer group • Satya’s fan club • Panel Discussion Group – To Percomp or not Percomp? • Imagine the richness of interaction that is possible!

3. Research Question? • What are the properties of a social group that concern us in regards to Ubicomp environments? • How do social groups relate to context aware computing? • Construction of an approach to leverage the properties of social groups.

4. Social Groups Defined in [1] as: A number of individuals, defined by formal or informal criteria of membership, who share a feeling of unity or are bound together in relatively stable patterns of interaction.

5. Persistence of a Social Group • Derived from the stability of membership and group interactions when compared against the lifetime of an average computing session • Generally cuts across computing session boundaries

6. Social Context • Information relevant to the characterization of a situation that influences the interactions of one user with one or more other users. • Social mores and norms are an example of a social context • Ex: It is a norm to consider a cell-phone ringing in a theatre as rude.

7. SmartClassroom Example • Peer review for a software engineering report • Student use special software on PDAs to support the review process as a team • Should work regardless of network infrastructure • Group has roles of reviewer, recorder, author, and moderator.

8. Example Cont. Start Peer Review =

9. Example Cont.

10. Example Cont. End Peer Review =

11. Challenges of Supporting Social Groups in Ubicomp Environments • Social Group Management • Sensing social context • View maintenance • Preserving privacy • Minimize user distraction – through proactiveness • Facilitating Group Communication • Determining when an interaction is going to occur • Determining when an interaction is going to end • Supporting periodic ephemeral interactions in environments with varying network capabilities

12. A Solution for Supporting Social Groups in Ubicomp Environments • System and Group Model • Context-Aware Ephemeral Group (CAEG) Membership Management • Group Chat Application • Prototype CAEG and Chat Application • Related Work • Conclusions

13. System Model- Idealized Future Pervasive Computing Environment • Users carry one or more ubicomp devices that can be networked wirelessly. • Ample bandwidth • Users need to collaborate using peer-to-peer application software over a mobile ad-hoc network. • No Byzantine failure in the system. • Clocks can be synchronized between devices within application tolerance limits.

14. Group Model Assumptions • Computer systems should facilitate the user’s view of the social group in terms of membership and collaborative interactions. • Feedback from user is desired, not full system automation: • Assumes that some mechanism for achieving consensus exists in regards to membership. • Likewise selecting discovering and joining a group can be non-trivial.

15. Group Model Introduction • Model addresses the need to facilitate group membership and routines with minimum system set-up. (minimize human distraction) • Goal is to support social groups in a manner that uses minimal cognitive effort, and gives the perception that a device is a group collaboration tool

16. Group Model Components • Definition of device context • Detailed description of group model • How does the system model support the detection of the beginning and ending of group interactions?

17. Device Context • Device Context – Any detectable and relevant attribute of a device, its interaction with external devices, and/or its surrounding environment at an instant of time.

18. Relationship of Groups in the Model Specifies device context that correspond to group session initiation and termination. Abstraction of social context Collaboration tool.

19. User Group • A social group that the end-user interacts with. • Expected to have stable patterns of interaction. • User Group Session: time period for which the members of a user group are actively participating in interactions with one another.

20. Device Group • One or more devices that form a complete unit in composition to collectively support computational tasks on behalf of the user-group. • User views this as a group that forms to facilitate group collaboration.

21. User Group Profile • Provides a representation of social contexts that are important to the user group. • Used by a device to support a user’s specific role or preferences. • Includes a unique identifier, user preferences, a group purpose, and the user’s role.

22. Group Session Profile • Used to represent the contexts that characterize the beginning and ending of a user group session. • Should include the time period of the group session, and the location where the group session will occur.

23. Support for Social Groups by Model • Supports user’s perception of identity that is tied to the group by automating device group formation using the GSP during the lifetime of group membership. • Uses social contexts in the UGP to support the users preferences and roles.

24. Context-Aware Ephemeral Group Membership Management • Uses context to manage a group view for devices over wireless ad-hoc networks • Contexts that govern group formation are based on the contexts found in the Group Session Profile

25. Reconfigurable Context-SensitiveMiddleware (RCSM) • RCSM is a middleware to enable context sensitive ad hoc interaction among devices in MANET. • Combines the power of abstraction of mainstream middleware specifications with the performance and economy of hardware.

26. Principal features • Context-Aware Interface Definition Language (CA-IDL) for specifying context-sensitive object interfaces for applications in pervasive computing environments. • An RCSM-Object Request Broker (R-ORB) to manage context-triggered communication channels among devices in mobile ad hoc networks. • Context-sensitive service distribution and discovery to facilitate optimized service information exchange among the devices. • Adaptive object containers (ADCs) that detect application-specific context and invokes the methods of context-sensitive objects. •  Support for Ephemeral Group Communication

27. RCSM (includes R-ORB) Ephemeral Group Communication Service Adaptive Object Container R-ORB (Software part) Situation-Aware Object Component Pool R-ORB Controller Component Message Delegator CORBA Object Context-Sensitive Object Context-Sensitive Object Embedded OS (e. g. Windows CE, Palm OS) Software Software-Hardware Interface (e. g. USB, Compact Flash, or PCI device driver) Hardware R-ORB (FPGA part) Local Object Interface Buffer R-GIOP Engine CORBA GIOP (Optional) Remote Object Data Cache Transport Interface Figure 6: A High-Level Architecture of RCSM. Context Processor Transport (e.g. Bluetooth, IrDA, Radiometrix, IEEE 802.15) Sensors RCSM Architecture

28. Group Chat Application • Uses the services provided by the CAEG to implement a chat application for Windows CE. • Allows users to communicate via unicast/multicast text messages, and exchange files.

29. Conclusions and Future Work • Explored the properties of the social group, and defined “social context” • Groups in Ubicomp environments need services to manage membership, and stable predictable routines • Defined a conceptual model that allows for the representation and interpretation of contexts to support group membership management and routines through context-awareness. • Usability testing

30. References • G. Marshall and et. all. The Concise Oxford Dictionary of Sociology. Oxford University Press, Great Britain, 1994. • For more information http://shamir.eas.asu.edu/~mcn or http://www.eas.asu.edu/~rcsm