Supporting Persistent Social Groups in Supporting Persistent Social Groups in Ubiquitous Computing Environments Using Ubiquitous Computing Environments Using

Context-Aware Ephemeral Group Management*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

Imagine You are @ Percom05 in Hawaii!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!

Research Question?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.

Social GroupsSocial 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.

Persistence of a Social GroupPersistence 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

Social ContextSocial 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.

SmartClassroom ExampleSmartClassroom 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.

Example Cont.Example Cont.

Start Peer Review

Example Cont.Example Cont.

Example Cont.Example Cont.

End Peer Review

Challenges of Supporting Social Groups Challenges of Supporting Social Groups in Ubicomp Environmentsin Ubicomp Environments

1. Social Group Managementa. Sensing social contextb. View maintenancec. Preserving privacy d. Minimize user distraction – through proactiveness

2. Facilitating Group Communicationa. Determining when an interaction is going to occurb. Determining when an interaction is going to endc. Supporting periodic ephemeral interactions in

environments with varying network capabilities

A Solution for Supporting Social A Solution for Supporting Social Groups in Ubicomp EnvironmentsGroups in Ubicomp Environments

System and Group ModelContext-Aware Ephemeral Group (CAEG)

Membership ManagementGroup Chat ApplicationPrototype CAEG and Chat ApplicationRelated WorkConclusions

System Model- Idealized Future System Model- Idealized Future Pervasive Computing EnvironmentPervasive Computing Environment

1. Users carry one or more ubicomp devices that can be networked wirelessly.

2. Ample bandwidth3. Users need to collaborate using peer-to-peer

application software over a mobile ad-hoc network.

4. No Byzantine failure in the system.5. Clocks can be synchronized between devices

within application tolerance limits.

Group Model AssumptionsGroup 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.

Group Model IntroductionGroup 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

Group Model ComponentsGroup Model Components

Definition of device contextDetailed description of group modelHow does the system model support the

detection of the beginning and ending of group interactions?

Device ContextDevice 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.

Relationship of Groups in the Relationship of Groups in the ModelModel

Specifies device context that correspond to group session initiation and termination.

Abstraction of social context

Collaboration tool.

User GroupUser 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.

Device GroupDevice 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.

User Group ProfileUser 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.

Group Session ProfileGroup 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.

Support for Social Groups by Support for Social Groups by ModelModel

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.

Context-Aware Ephemeral Group Context-Aware Ephemeral Group Membership ManagementMembership 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

Reconfigurable Context-SensitiveReconfigurable Context-SensitiveMiddleware (RCSM)Middleware (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.

Principal featuresPrincipal 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

RCSM ArchitectureRCSM Architecture

Software

Hardware

Transport (e.g. Bluetooth, IrDA, Radiometrix, IEEE 802.15)

Sensors

R-ORB (FPGA part) Local Object Interface Buffer R-GIOP Engine

Remote Object Data Cache Transport InterfaceContext Processor

CORBA GIOP (Optional)

RCSM (includes R-ORB)

Adaptive Object Container

Situation-Aware Object

CORBA Object

Ephemeral Group Communication Service

R-ORB (Software part)

Component Message Delegator

R-ORB ControllerComponent Pool

Embedded OS (e. g. Windows CE, Palm OS)

Figure 6: A High-Level Architecture of RCSM.

Context-Sensitive Object

Context-Sensitive Object

Software-Hardware Interface (e. g. USB, Compact Flash, or PCI device driver)

Group Chat ApplicationGroup 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.

Conclusions and Future WorkConclusions 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

ReferencesReferences

1. G. Marshall and et. all. The Concise Oxford Dictionary of Sociology. Oxford University Press, Great Britain, 1994.

2. For more information http://shamir.eas.asu.edu/~mcn or http://www.eas.asu.edu/~rcsm