Pervasive Computing from Wireless Microservers to Active Spaces

1
Pervasive Computing from Wireless Microservers to
Active Spaces

• Bernadette A. Carter
• Laurent B. Vauthrin

2
Papers

• Hartwig, Stephan, Jan-Peter Stromann, and Peter
  Resch. "Wireless microservers."
• IEEE Pervasive Computing. Vol. 1, No. 2,
  April-June 2002, pp. 58-66.
• Roman, Manuel, et al. "A Middle Infrastructure
  for Active Spaces." IEEE Pervasive Computing.
  Vol. 1, No. 4, October- December 2002, pp. 74-83.

3
Pervasive Computing

• A shift towards ubiquitous computing systems
• Intended to provide an enhanced living
  environment with digital information and
  processing.

4
Wireless Microservers
5
Background

• Microserver-a small, cost-efficient web-server
  that is integrated or plugged directly into a
  device
• Nokia and the University of Dortmund have created
  a low-power wireless microserver.

6
Possibilities

• Real interaction instead of one-way commands
  being sent from the user.
• Location-aware computing
• Limit the redundancy of commands amongst multiple
  devices
• Provide Internet access to devices without using
  a PC.

7
Microserver Implementation Questions

• What device should be used to connect to the
  wireless microserver?
• How should service discovery be implemented?

8
Connection to Wireless Microserver

• Mobile phone vs. PDA
• Though the PDA may have more resources, the
  mobile phone was selected because it is more
  prevalent in todays society.

9
Service Discovery

• Bluetooth- short-range radio technology
• 2 ways to setup connection
• User request-searches for all Bluetooth devices
  in the users proximity
• Discoverable mode-once the user terminal comes
  into the proximity of a Bluetooth device, the
  terminal is alerted.

10
Embedded vs. Pluggable Server
11
Implementation Options for Distribution of UI to
pluggable servers

• Preprogramming server with user interface (UI)
  for several devices
• Server downloads UI from the device.
• Server downloads UI from the Internet by being
  connected to a PC
• Server downloads UI by connecting to the Internet
  using a mobile phone.

12
1. Preprogrammed Server

• Advantages Minimizes effort needed from users
  connection device or by the manufacture company
  of the device the server is connected to
• Disadvantages Unnecessary cost , may not have
  the proper UI for the users device

13
2. Server downloads UI from device

• Advantages Server is cheaper
• Disadvantages Device is more expensive,
  Difficult to update UI

14
3. Server downloads UI from Internet using PC
connection

• Advantages Easier to update user interface
• Disadvantages Requires more effort from the user

15
4. Server downloads UI from Internet using
mobile phone

• Advantages One server fits all,
  Advertisements may be shown to users, Easy to
  upgrade UI, generate more profit by offering a
  basic UI and a premium UI
• Disadvantages Cost of air-time for the mobile
  phone to download the UI

16
Implementations

• Author implemented a WAP application to control
  PowerPoint presentations using a Bluetooth phone.
• Author implemented a MP3 player play list editor
  running on a Bluetooth-equipped laptop
• Currently software is available to control a
  computer running a Mac OS using a Bluetooth
  enabled phone.

17
A Middleware Infrastructure for Active Spaces

• Physical Space is geographical area and the
  items contained within it.
• Active Space context-aware coordinated physical
  space.
• Goal Allows users to interact the environments
  resources seamlessly.
• Solution Use Gaia meta-operating system.

18
Gaia Overview
19
Gaia Kernel CMC

• Component Management Core Manages basic
  software unit.

Rest of the System
Node
Containers
Component
20
Gaia Kernel Services

• Context Service
• Context File System
• Component Repository
• Event Manager
• Presence Service
• Space Repository
• Security Service

21
Gaia Kernel Context Services

• Context Service
• Defines context properties and operations that
  can be performed.
• Context providers (kept in registry) sensors
  or other components which can infer context.
• Boolean algebra
• Context(temperature, room 3231, is, 98F)

ContextType
Subject
Relater
Object
22
Gaia Kernel Context File System

• Context File System
• Two modes of operation
• File traditional directory hierarchy
• Context directory structure based on context
• Easier for application to find information on
  their own.
• If we are looking for Type ppt Situation
  term-presentation then we go to
  /type/ppt/situation/term-presentation

23
Gaia Kernel Component Repository Event Manager

• Component Repository keeps copies of all
  components. Allows browsing, storing, and
  uploading.
• Event Manager provides means of communication
  using a consumer/supplier model.

24
Gaia Kernel Presence Service

• Notifies the active space of the state of the
  entities
• Supplies events on presence channels (different
  channels for people, devices, services).
• Software components notify their existence using
  a heartbeat (sent at a regular interval).
• People are discovered through sensors.

25
Gaia Kernel Space Repository Security

• Space Repository (database) keeps track of all
  active devices/services available in the space.
• Information is kept in XML format so that it can
  be queried easily
• Security still in development.
• Uses modules separate from application to handle
  authentication
• Sensors bring up a privacy issue.
• Gaia uses Mist protocol which allows for
  separation of identity and location.

26
Gaia Application Framework

• MVC (Model View Controller) bad fit for Gaia.
• Gaia MPCC (Model Presentation Controller
  Coordinator) decoupling of hardware and software.

27
Gaia Applications

• iCalendar - schedules
• Attendance - records participants for a task
• MP3Player - plays music to various speaker
  devices
• mPPT - displays multiple synchronized PowerPoint
  presentations 
• PDFViewer - displays Adobe PDF files on one or
  more display
• PPTViewer - displays PowerPoint presentations
  on displays and handhelds
• TickerTape - scrolls information around the room
  displays
• FingerPrint - authenticates people through
  finger print matching.

28
Questions?