A Framework for the Reconfiguration of Ubicomp Systems

Pau Giner, Carlos Cetina, Joan Fons, Vicente Pelechano

IntroductionBackgroundThe proposalThe reconfiguration frameworkConclusions and further work

Agenda

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IntroductionBackgroundThe proposalThe reconfiguration frameworkConclusions and further work

Agenda

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Ubicomp Systems

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Invisibility means to cope with different… …environments …users …devices

…to provide a natural interaction.

Some words regarding invisibility

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Many different devices and user preferences involve many configuration options Services can be combined in different ways Users have different demands regarding the

system behavior

The need for configuration

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Simplicity

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To achieve invisibility for the system, operation and configuration should be simple We propose the autonomous reconfiguration of

the system

IntroductionBackgroundThe proposalThe reconfiguration frameworkConclusions and further work

Agenda

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Background: PervML

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9

<<Service>>Presence

Simulation

<<Service>>Presence Detection

<< Service>>Alarm

<<Trigger>> Random

Simulation Starter

<< Trigger>>Presence Detected

<< BP>>PerimeterDetector

<< BP>>Infrared Detector

<< BP>>Visual/Acoustic

Alarm

<< Interaction>>Security

<< BP>>Silent Alarm

<< BP>>Automated Lighting

<< BP>>Volumetric

Detector

<< BP>>Blink

Lighting

<< BP>>Buzzer

<< Service>>Automated Lighting

Main concepts:•Service coordinates the interaction among providers (hardware or software).•Binding provider (BP) technology adapters .•Interaction sequence of invocations between services.•Trigger changes in the environment.

A Domain Specific Language for the specification of Pervasive

Systems.

PervML Example

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Security Service in a Smart Home

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Security Service

Presence DetectedTrigger

Motion Detector

Contact Sensor

Alarm

Technical details:European Installation Bus (EIB) devices

Presence DetectionService

Code generation capabilities

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Ab

stra

ction

Lev

el

-

+

EIB BlueTooth UPnP ...

OSGi

Framework

PervML models

Generated Code

Model Generate Deploy Change Model

IntroductionBackgroundThe proposalThe reconfiguration frameworkConclusions and further work

Agenda

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The idea

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Options for service composition

Behavior desired by users

Feature modelingPolicy definition

The idea

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Feature modelingPolicy definition

I offer a compact representation of

information Since I access the system using my mobile phone, I

need a compact representation of

information

General properties are used to connect both aspects

Capture system variability Using Feature Modeling

Define properties of interest Indicate which system components fulfill them

Create Policies Indicate which properties are required

Activate Policies (in run-time) The system is reconfigured to better fulfill the

demanded properties

Proposal Overview

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Feature modeling

Capture system variability

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Smart Home

Presence Detection

Perimeter Detection In home Detection

Infrared 160 degree DetectionVolumetric 360 degree

Detection

Presence Simulation

Alarm

SilentAlarm Visual/Acoustic

Alarm

Security

Siren

Automated Illumination

Description of a system and its variants.

Relationships: OptionalMandatoryOr-relationshipAlternative

Relevant properties are defined E.g., compact interaction, activity simulation, house

emptiness Features are qualified according to their

fulfillment Complete, partial or none

Define properties of interest

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A policy defines a set of assertionsEach assertions requires, prefers,

discourages, forbids some propertyCan be created by designers or end-users

Create Policies

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Activate policies

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IntroductionBackgroundThe proposalThe reconfiguration frameworkConclusions and further work

Agenda

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The reconfiguration framework extends the PrvML framework Based on OSGi for dynamicity

▪ Using Equinox implementation

▪ The variability model is kept and queried at runtime

Providing new components:▪ Characterization

▪ Analyzer

▪ Reconfigurator

The reconfiguration framework

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Overview

The reconfiguration framework

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Characterization component Collects al the assertions from the active

policies▪ Serialized as XML

Inconsistencies are managed▪ Restrictive assertions are prioritized

The reconfiguration framework

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Analyzer component Decides which features to activate to fulfill the

properties▪ OCL is used to query models at runtime

A conservative approach▪ A change is produced only when the system

improves the property coverage

The reconfiguration framework

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Reconfigurator component Once a feature is (de)activated, the

corresponding services and resources must be (dis)connected▪ The code for these has been generated by PervML

OSGi Wire class is used▪ To support publish/subscribe pattern

The reconfiguration framework

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Presence detection Service

Motion detector

Contact sensor

IntroductionBackgroundThe proposalThe reconfiguration frameworkConclusions and further work

Agenda

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The main goal was to provide PervML systems with reconfiguration capabilities The obtained framework can be used out of the

methodThe application to more case studiesBetter management of policy scope and

definition

Conclusions and further work

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ThankS