context awareness in mobile computing

Context Awareness in Mobile Computing

The Revolutionary Impact of Pervasive Mobile Computing

Bob [email protected] Ilmu Komputer, Universitas Indonesia

SRITI 2011 Seminar Riset Tenologi Informasi

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SRITI 2011 - Seminar Riset Tenologi Informasi2

Pervasive – Ubiquitous – Mobile Computing

Low

High

Low HighLevel of mobility

Level of embeddedness

Ubiquitous Computing

MobileComputing

Traditional Business

Computing

PervasiveComputing

[1]

SRITI 2011 - Seminar Riset Tenologi Informasi

Mobile Computing: the Next Decade

Scenario 1: Lost Child

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Scenario 2: Disaster Relief

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Scenario 3: Cognitive Assistance

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Scenario 4: Medical Consultation

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Reflecting on these Scenarios [3]

Embody a number of themes Rich sensors Crowd sourcing Near-real-time data consistency Opportunism Transient use of infrastructure User interaction

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Reducing Distraction

User attention is a precious resource

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The most successful mobile computing systems of the next decade will be those that are able to reduce or eliminate user interactions


User Interaction with Mobile Device

Mobile application autonomy can reduce user interaction.

Mobile application should place greater dependence on contextual information

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Context Definitions

Context defined variously as: An application/user’s environment or situation A combination of computing, user and physical features

Definition from Dey & Abowd [2]:“Context is any information that can be used to characterise the situation of an entity. An entity is a person, place or object that is considered relevant to the interaction between a user and an application, including the user and the application themselves.”


Context Awareness

Context of computation may change

Context of computation may be (partially) captured by context information

Context information can be used to provide seamless computing provide relevant services to users

Needed: Information about requirements and current status of computations and their environments


Context Information - Example

user location, devices, applications

user preferences and QoS requirements

application QoS requirements and status

device and network capabilities and their current status

relationships between context information


Context Awareness & Mobile Apps

Context-aware applications tend to be enhanced mobile applications for the following reasons: User context changes frequently subject to the user’s

mobility behavior The need for context-aware behavior is greater in a

mobile environment (user location, network resources, and device capabilities)

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Context-Aware Logic Space [4]

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Proximity selection

Proximity selection is primarily based on the user location context

Such context can be: resources and devices in the vicinity of the user places of interests closest to the user current position computational objects with which the mobile user is

currently interacting

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Context Modeling

Modeling context is a technique focuses on how to find and relate contextual information that better captures the observation of certain worlds of interest

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Context Modeling - Example

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Person(name)

Device(id)

Location(name)

has device

located at

Conceptual model (CML)

Logical model (relational model) HasDevice(Person, Device)

LocatedAt(Person, Location)

Maps to


Person(name)

has device

Device(id)

Profile(code)

has profile

Base Station(nr)

Location Type(Name)

Network Strength

(nr)

Phone Number(nr)

Number Type(name)

Divert Status(name)

Allow Status(nr)

Disruption Level(name)

has nearest base station

has network strength

has location type

has phone number has number type

has disruption level

has allow status

has divert status

has divert type

Person(name)

has device

Device(id)

Profile(code)

has profile

Base Station(nr)

Location Type(Name)

Network Strength

(nr)

Phone Number(nr)

Number Type(name)

Divert Status(name)

Allow Status(nr)

Disruption Level(name)

has nearest base station

has network strength

has location type

has phone number has number type

has disruption level

has allow status

has divert status

has divert type


Context-Aware Application

Context acquisition

Context aggregation

Context consistency

Context discovery

Context query

Context adaptation

Context reasoning

Context quality indicators

Context integration

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A Context-aware application should have a set of characteristics related to context modeling, handling, adaptation:


Typical Architecture

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Context Manager

Context Gathering & Processing Layer

Middleware

Programming Toolkit

Context-Aware Applications

SensorSensorSensor

ContextModel

PreferenceManager

Context Manager

Context Gathering & Processing Layer

Middleware

Programming Toolkit

Context-Aware Applications

SensorSensorSensor

ContextModel

PreferenceManager


User Control of Context-Aware Mobile Apps

Context-aware mobile application may not always behave in the way users expected, due to Imperfect context information Incorrect user preferences Incorrect adaptation rules

Users may feel loss of control over their application.

The system must provide mechanisms to strike a suitable balance of control

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Balance of User Control

A continuum of user control versus application autonomy

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User controlApplication autonomy

A B C


Providing Suitable Balance of Control

Make users aware of reasons for application adaptation

User may be able to correct undesirable actions

Users may have varying levels of expertise

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Exposing the System’s view

Exposing system’s view of the context and its corresponding actions provides a sufficient understanding to correct inappropriate action (increases user control)

An appropriate modelling of context and preference is needed for revealing the information to the users

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Users

User Preferences

Adaptation Logic

Context Information

Context-aware System

Interactions


Context & Preference

Manager

Context and preference change Information Filter

&Explanation Generator

Exposed application state information

User PreferenceDatabase

User Preference

User feedback

Informationrequest (scrutinize)

ContextDatabase

TracesDatabase

Programming Toolkit

De

sc

rip

tio

ns

Co

nte

xt

Gra

ph

Us

er

Mo

de

l

Semantic Manager

USER

Example Approach


Context and Preference Manager

Semantic Manager

Context and Preference Proxy

ContextClient

Outside World

WebInterface

ContextWindows

User

contextchanges

contextchanges

preferencesand profile information

inquiry(scrutinizing)

revealedinformation

contextchanges

User interaction

Con

text

-Aw

are

App

licat

ion

context andpreference changes

context informationand preference

evaluation scores


Summary

User attention is a precious resource in mobile environment

Mobile application should reduce user interaction

Mobile application should place greater dependence on context

Need balance of user control due to imperfect context information

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References

[1] K. Lyytinen, Y. Yoo, Issues and Challenges in Ubiquitous Computing, CACM, Vol.4, No.12, 2002

[2] A. K. Dey and G. D. Abowd, Towards a better understanding of context and context-awareness. In CHI 2000 Workshop on the What, Who, Where,vWhen and How of Context-Awareness. The Hague, April 2000.

[3] M. Satyanarayanan, Mobile computing: the next decade, in MCS '10 Proceedings of the 1st ACM Workshop on Mobile Cloud Computing & Services: Social Networks and Beyond, 2010

[4] Christos B. Anagnostopoulos , Athanasios Tsounis , Stathes Hadjiefthymiades, Context Awareness in Mobile Computing Environments, Wireless Personal Communications: An International Journal, v.42 n.3, p.445-464, August 2007

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TERIMA KASIH

context awareness in mobile computing

Technology

context definitions

context informationsriti

user context changes

user control of context

mobile user

contextaware behavior

contextaware logic space

user interactionssriti