The Gaia System. 6.893 Spring 2004: Gaia Larry Rudolph Not Invented Here Lots of Pervasive Computing Projects Carnegie Mellon Univ. U. Washington Georgia.

The Gaia System

6.893 Spring 2004: Gaia Larry Rudolph

Not Invented Here

Lots of Pervasive Computing Projects

Carnegie Mellon Univ.

U. Washington

Georgia Tech

UC Berkeley

Univ. Illinois Urbana ChampaignGaia

England & Scandinavia & ??


Similarities

Pervasive computing can be characterized as:

Extensive management for components (services, devices)

Components are autonomous

Some application programming support:

Java or Python

Rules or scripts

Still very primitive (in my opinion)


Mid

dlew

are

Gaia Architecture

Gaia

Kernel

EventManager

ContextService

ContextFile

System

ComponentRepository

PresenceService

SpaceRepository

ResourceManagement

Service

ApplicationFramework Configuration

ManagementService

QoSInstantiation

Service

QoSTranslation

Service

QoSAdaptation

Service

Applications

Component Management Core



Provides functionality to manipulate components in Gaia:

Creation

Destruction

Uploading

Contains three basic abstractions:

Components

Component Containers

Nodes



Gaia Components

Gaia Component ContainerGaia Node Examples

Gaia Node

Active Space

Gaia Component ContainerGaia Node


Gaia Kernel Services

Event Manager

Context Service

Context File System

Component Repository

Presence Service

Space Repository


Event Manager

Loosely coupled communication based on channels.

Supports push, pull, and hybrid mechanisms.

Supports creation of named event channels and distribution of load.


Event Manager

Event Manager

Event ChannelFactory 1

. . .Event Channel

Factory n

CreateChannelTypeDeleteChannelTypeCreateEventChannelGetEventChannelDeleteEventChannelListChannelTypesListEventChannels

ConsumersConsumers

Suppliers Suppliers

EventChannels


Context-Aware Applications

Situational information, or context, increases richness of communication in human-computer interaction.

Makes it possible to produce more useful computational services.

Example contexts: location, time, weather, stock prices, moods, user activity, …


Context Service

Provides a taxonomy and uniform representation of context types.

Provides an infrastructure to promote design, implementation, and evolution of context-aware applications.


Context File SystemData Organization:

Context affects data organization.

Data important in current context is easily accessible.

Can attach context to files and directories.

Context: situation, location, space, group, time.

Data Transformation:

Applications open data as desired type – dynamically typed file system.

System converts data to desired type.


Data Organization

space = officelocation = RM2401time = 11/28/01


Data Transformation

MPEGContainer

MPEG

Pixel2BitmapConverter

Text2AudioConverter

GIF2PixelConverter

Pixel2BitmapConverter

BitmapContainer

AudioContainer

MailContainer

PowerPointContainer

MailPowerPoint

BitmapContainer

MP3Container

MP3

PCM2GSMConverter

GSMContainer


Component Repository

Provides persistent storage of components.

Allows addition, removal, and browsing of components.

Used by Component Management Core to dynamically retrieve components.


Presence ServiceDetects the presence of digital and physical entities.

Generates events based on entity presence:

ENTER

LEAVE

Defines a group of event channels to disseminate presence information.

Maintains soft-state of all digital entities through a leasing mechanism.


Presence Service

Digital Entity

Presence

Physical Entity

Presence

Person Tracker

Application

Service

Device

Person

Event Manager Channels

Dev

ice

Pre

senc

e C

hann

el

Per

son

Pre

senc

e C

hann

el

Ser

vice

Pre

senc

e C

hann

el

App

lica

tion

Pre

senc

e C

hann

el

EnterLeaveEvents


Space RepositoryCentralized repository containing information about active entities.

Interacts with Presence Service to keep information up to date.

All entities described by a set of properties (e.g., entity type, name, location, owner).

Exports a query interface based on properties.


Space Repository

DetectionMechanism

Database

Presence Channels

ComponentQ

uery

Int

erfa

ce

Component

Component


Application Framework

Active Spaces render traditional applications obsolete.

Applications for Active Spaces are:

Distributed

Adaptable

Mobile

Multi-Machine User Interface


Traditional Application Mapping

Display

Controller

ApplicationLogic


Active Space Active Space Application MappingApplication Mapping

Controllers

Displays

ApplicationLogic


Model – Presentation – Controller – Coordinator Application Framework

Coordinator

ApplicationFunctionalLevel

Application Meta-Level

MPCC Application

Model

Slide ShowData

Controllers Presentations


Model – encapsulates the application logic.

Presentation – presents the data of the model (audio, video, changes in the physical environment).

Controller – modifies the state of the model.

Coordinator – manages the application architecture (application meta-level).

MPCC Application Framework


QuickTime™ and aTIFF (LZW) decompressor

are needed to see this picture.








Application Generic Description




Application Concrete Descp.







Applications

Mobile Video

Context Data Browser

Presentation Viewer


Mobile Video

Media Server

ComponentDatabase

Location A Location BMove!

User ProfileServer

Media Gateway


Context Data Browser

File Mode

Context Mode


Presentation Viewer








The Context Model

Enables creation of complex, first-order expressions involving context

Makes it possible to write rules, prove theorems, evaluate queries


Basic Structure

Four parts:

context-type

Subject: Person, place, or thing

Relater: something that related subject to object

Object: is a value associated with subject


Some examples

Context(Location, Chris, Entering, G868)

Context(Temperature, G868, Is, 98F)

Context(Stock Quote, IBM, >, $60 )

Context(Printer Status, Pulp, Is, Empty)

Context(Time, New York, Is 12:00 01/01/04)


Operations on Contexts

Boolean, Existential, Quantification

Context(lighting, G868,Is,Off) OR

Context(lighting, G828,IS, Dim)


Context Chat

The Gaia System. 6.893 Spring 2004: Gaia Larry Rudolph Not Invented Here Lots of Pervasive Computing Projects Carnegie Mellon Univ. U. Washington Georgia.

Documents

gaia system

current context

evolution of context

components services

data important

extensive management

typed file system

applications open data