A Middleware Infrastructure for Active Space GAIA

1
A Middleware Infrastructure for Active Space
(GAIA)

• School of Computer Science
• UIUC(00 )
• Supercomputing Lab.
• Joo-kyoung Park

2
Contents

• Introduction
• Active Space
• System software
• Gaia Kernel
• Application Framework
• Gaia management tools
• Scripting language
• Example

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Introduction

• Characteristic of Ubi-Env.
• Device-rich, Context-aware environment
• Very highly dynamic
• Problem of programming Ubi-Env.
• The resource and context can change rapidly
• Developer can not expect to know how various
  tasks are performed
• Program must be able to adapt the changing
  context and resource
• ? Can solve as Management Framework

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Active Space(1/2)

• Definition
• A physical space coordinated by a responsive
  context-based software infrastructure
• Physical space
• A geographic region with limited and well-defined
  physical boundaries
• Object of Active space
• Support the development and execution of
  user-centric mobile applications
• Simplify application programming and execution

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Active Space(2/2)

• Characteristic of Active space
• A one-to-one relationship between a user and
  keyboard, mouse, and display interfaces does not
  exist

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Gaia System software

• Gaia manages an active spaces resources and
  services
• Provides location, context, and event services
  and stores information about the active space
• Gaia is composed kernel, the application
  framework, and the applications

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Gaia kernel(1/4)

• Consists of a component management core and an
  interrelated set of basic services used by all
  Gaia applications.

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Gaia kenel(2/4)

• Component management core
• Dynamically loads, unloads, transfers, creates,
  and destroys all Gaia components and applications
• Five basic services
• Event manager
• Distributes events in the active space
• Implements a decoupled communication model based
  on suppliers, consumers, and channels
• Context service
• Applications query and register for particular
  context information through Context service
• Infer certain higher-level contexts on the basis
  of sensed information

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Gaia kernel(3/4)

• Context service
• An atomic context predicate is defined as
  Context(, ,
  ,)
• Ex. Context(temperature, room 3231, is, 98 F)
• Presence service
• Must maintain updated information about active
  space resources.
• Digital-entity presence Subsystem
• Detects service and application entities
• Physical-entity presence Subsystem
• Detects devices and people present in the active
  space.

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Gaia kernel(4/4)

• Space repository
• Stores information (name, type, owner, and so on)
  about all software and hardware entities
• Retrieve entities on the basis of specific
  attributes.
• Context file system
• Provide automatically available context in the
  users current location
• Make and organize personal data automatically
  available to applications, conditioned on user
  presence
• Constructs a virtual directory hierarchy based on
  the types of context
• Retrieve data in a format based on user
  preferences or device characteristics

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Application Framework(1/6)

• Lets users construct, run, or adapt existing
  applications to active spaces
• Application Framework consist of
• A distributed component-based infrastructure
• A mapping mechanism
• A group of policies
• Infrastructure
• Use MVC model

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Application Framework(2/6)

• Definition of MVC design pattern
• Used by App. that need to maintain multiple views
  of the same data
• Component of MVC design pattern
• Model
• Maintaining the data
• View
• Displaying the data
• Controller
• Handling events that affect the model or views

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Application Framework(3/6)

• General structure of MVC
• Example of MVC

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Application Framework(4/6)

• Extended MVC model
• The model implements the application logic.
• The presentation display the application data.
• The input sensor lets the user interact with the
  application.
• The controller maps input sensor events (such as
  touch-screen events and context changes) into
  method requests for the model.
• The coordinator manages the first four components

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Application Framework(5/6)
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Application Framework(6/6)

• A mapping mechanism
• AGD(Application generic description)
• Created by the application developer
• Listing the application components, the minimum
  and maximum number of instances allowed, and
  component requirements
• ACD(Application customed description
• Implemented as a script that coordinates the
  instantiation and assembly of the different
  components
• Customization policies
• The application framework relies on policies to
  address reliability, adaptation, mobility, and
  related issues

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Gaia Management tools

• Relies on a scripting language to coordinate the
  digital-entities running in an active space.
• Scripting language
• uses a high-level scripting language, LuaOrb,
• Program and configure active spaces and to
  coordinate the active entities

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Registering with the active space
Active space
4.Accesses the user profile, obtains the
speakers mount points, and mounts the data in
the space
5.The speaker registers the handheld and
periodically sends a heartbeat signal
CFS
Event
Event
7.contacts the device to retrieve the XML
description, and stores the information
Presence Service
Space Repository
6.Receives the event and sends a new event to the
device presence channel
Event
2.Event contains information about the speaker,
including a reference to users preference
3.Retrieves an XML description for the user
entity, and stores the information
1.Presence service detect badge and send an event
to the person presence channel
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Starting the application
1.Register with the context service to be
notified when the room context meets this
condition
3.When the user data is mounted in Active Meeting
Room 2401
Context Service
4.the trigger service requires a valid ACD
Trigger action Application
Trigger Service
Lua Script
Presentation Manager
ACD (Lua Script)
2.Gets the presentation files name and starts
the presentation manager