ISA5428: 普及計算
Pervasive Computing:
An Overview
金仲達教授
清華大學資訊系統與應用研究所
九十三學年度第一學期
(Some slides are taken from the presentation by
Prof. Friedemann Mattern of ETH Zurich)
Outline
The Vision -- According to Mark Weiser
 The Enablers
 Example Projects
 Summary

Overview-1
Pervasive Computing
According to Mark Weiser
Overview-2
Transparencies Are Taken from

Mark Weiser's slides for the keynote speech
"Building Invisible Interfaces" given at the User
Interface, Systems, and Technologies (UIST)
Conference, November, 1994.
 Mark Weiser’s slides from the invited talk: "Does
Ubiquitous Computing Need Interface Agents?
No." given at the MIT Media Lab Symposium on
User Interface Agents, October 1992.
 M. Weiser’s paper “The Computer for the 21st
Century,” Scientific American, Sept. 1991.
Overview-3
Your Personal Experience
Remember the last time you spent several
productive hours?
 It had some characteristics:

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Time passed unnoticed
You were unaware of your surroundings
Consciously you focused on a goal
Unconsciously you drew on tacit skills and knowledge
The situation was very rich with details and nuances
that you unconsciously took into account
The things you did not think about – the tacit,
the context, the world – made you smart!
Overview-4
A Basic Characteristic of Human
People are most effective and authentic when
they are fully engaged, mind and body, in the
world
 Examples:
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Flow of the athlete in the groove
Effortless use of pencil, paper and language when
writing
Effortless 65 MPH driving of the experienced driver
(while talking, reading road signs, …)
Technologies should enhance this ability to
engage, to “flow” with life and work
Overview-5
Invisible Technologies

The most powerful technologies are invisible:

Electricity
they get out of the way to let human be
effective

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Electric motors hidden everywhere (20-30 per car)
Electric sockets in every wall and portably available
through batteries
Integrated, invisible infrastructure
Literary technology


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Continuously surrounding us at many scales: books,
newspapers, street signs, candy wrappers
Used trivially and profoundly
Literally visible, effectively invisible
Overview-6
Good Technology Is Invisible

“Invisible” stays out of the way of task

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Bad technology draws attention to itself, not task
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Like a broken, or skipping, or dull pencil
Like a car that needs a tune-up
Computers are mostly not invisible


Like a good pencil stays out of the way of the writing
Like a good car stays out of the way of the driving
They dominate interaction with them
Ubiquitous computing is about “invisible
computers”
Overview-7
How to Do Invisible Computing?

Integrated computer systems approach

Invisible, everywhere, computing named “ubiquitous
computing” in April 1989
Invisible: tiny, embedded, attachable, …
 Everywhere: wireless, dynamically configurable,
remote access, adapting, …

Overview-8
Overview-9
Goals of Ubiquitous Computing

Ultimate goal:
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Invisible technology
Integration of virtual and physical worlds
Throughout desks, rooms, buildings, and life
Take the data out of information, leaving behind just
an enhanced ability to act
Overview-10
Ubicomp Phase I

Phase I
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Smart, ubiquitous I/O devices: tabs, pads, and boards
Hundreds of computers per person, but casual, lowintensity use
Many, many “displays”: audio, visual, environmental
Wireless networks
Location-based, context-aware services
Interesting scenarios
Using a computer should be as refreshing as a
walk in the woods
Overview-11
Smart Objects

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Real world objects are
enriched with information
processing capabilities
Embedded processors
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Communication capability
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in everyday objects
small, cheap, lightweight
wired or wireless
spontaneous networking
and interaction
Sensors and actuators
Overview-12
Smart Objects (cont.)

Can remember pertinent events

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Show context-sensitive behavior
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They have a memory
They may have sensors
Location/situation/context
awareness
Are responsive/proactive

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Communicate with environment
Networked with other smart objects
Overview-13
Smart Objects (cont.)
Overview-14
Ubiquitous Computing Vision
“In the 21st century the technology revolution will
move into the everyday, the small and the
invisible…”
“The most profound technologies are those that
disappear. They weave themselves into the
fabrics of everyday life until they are
indistinguishable from it.”
Mark Weiser (1952 –1999), XEROX PARC

Small, cheap, mobile processors and sensors
in almost all everyday objects
on your body (“wearable computing”)
embedded in environment (“ambient intelligence”)
Overview-17
Outline
The Vision -- According to Mark Weiser
 The Enablers
 Example Projects
 Summary

Overview-18
First Enabler: Moore‘s Law

Processing speed and storage capacity double
every 18 months


“cheaper, smaller, faster”
Exponential increase

will probably go on for the next 10 years at same rate
Overview-19
Generalized Moore’s Law

Most important technology
parameters double every 1–
3 years:
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computation cycles
memory, magnetic disks
bandwidth
Problems:
• increasing cost
• energy
Consequence:

scaling down
Overview-20
2nd Enabler: Communication

Bandwidth of single fibers ~10 Gb/s

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Powerline
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coffee maker “automatically” connected to the Internet
Wireless
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2002: ~20 Tb/s with wavelength multiplex (often at no cost for
laying new cable!)
mobile phone: GSM, GPRS, 3G
wireless LAN (> 10 Mb/s)
Bluetooth
Room networks, body area networks
Internet-on-a-chip
Overview-21
Ubiquitous Information
PAN: Personal area network
Overview-22
Body Area Networks
Very low current (some nA), some kb/s through
the human body
 Possible applications:

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Car recognize driver
Pay when touching
the door of a bus
Phone configures itself
when it is touched
Overview-23
Spontaneous Networking

Objects in an open, distributed, dynamic world
find each other and form a transitory community

Devices recognize that they
“belong together”
Overview-24
3rd Enabler: New Materials

Important: whole eras named after materials

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More recently: semiconductors, fibers

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change the external appearance of computers
“Plastic” laser

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information and communication technologies
Organic semiconductors

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e.g., “Stone Age”, “1st generation computers”
Opto-electronics, flexible displays,…
...
Overview-25
Smart Paper, Electronic Ink

Electronic ink
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micro capsules, white on one
side and black on the other
oriented by electrical field
substrate could be an array of
plastic transistors
Potentially high contrast, low
energy, flexible
 Interactive: writable with
magnetic pen

Overview-26
Interactive Map

Foldable and rollable
You are here!
Overview-27
Smart Clothing

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Conductive textiles and inks
 print electrically active
patterns directly onto fabrics
Sensors based on fabric
 e.g., monitor pulse, blood
pressure, body temperature
Invisible collar microphones
Kidswear
 game console on the sleeve?
 integrated GPS-driven locators?
 integrated small cameras (to
keep the parents calm)?
Overview-28
Smart Glasses

By 2009, computers will disappear. Visual
information will be written directly onto our
retinas by devices in
our eyeglasses and
contact lenses
-- Raymond Kurzweil
Overview-29
Today’s Wearable Computer
ready to ware
Overview-30
Wearable Concept (Motorola)
Overview-31
4th Enabler: Sensors/Actuators
Miniaturized cameras, microphones,...
 Fingerprint sensor
 Radio sensors
 RFID
 Infrared
 Location sensors

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e.g., GPS
...
Overview-32
Example: Radio Sensors

No external power supply

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energy from the
actuation process
piezoelectric and
pyroelectric materials
transform changes in
pressure or temperature
into energy
RF signal is transmitted via an antenna (20 m distance)
Applications: temperature surveillance, remote control
(e.g., wireless light switch),...
Overview-33
RFIDs (“Smart Labels”)

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Identify objects from distance
 small IC with RFtransponder
Wireless energy supply
 ~1m
 magnetic field (induction)
ROM or EEPROM (writeable)
 ~100 Byte
Cost ~$0.1 ... $1
 consumable and disposable
Flexible tags
 laminated with paper
Overview-34
Bar Code Reader

PDAs, mobile phones, and wireless Internet
appliances become request devices for
information
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find information
order products
...
Overview-35
Lego
Making Lego
Smart:
Robot command
Explorer (Hitachi
H8 CPU, 32KB
RAM, IR)
Overview-36
Lego Mindstorms
Overview-37
Putting Them Altogether

Progress in
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computing speed
communication
bandwidth
material sciences
sensor techniques
computer science
concepts
miniaturization
energy and battery
display technologies
...

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Enables new
applications
“Post-PC era”
business
opportunities
Challenges for
computer scientists,
e.g., infrastructure
Overview-38
Outline
The Vision
 The Enablers
 Example Projects
 Summary

Overview-39
Idea: Making Objects Smart
The Smart Its Project

Vision: make everyday objects
as smart, interconnected
information artifacts

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by attaching “Smart-Its”
Smart labels

Atmel microcontroller:
(ETH Zurich)
4 MIPS, 128 kB flash
Overview-40
“Smart-Its Friends”
How do we establish that two objects “belong
together”?
 Hold them together and shake!

Overview-41
“Smart-Its Friends”!

After the shared context has been established,
the two devices can open a direct
communication link to exchange applicationspecific data
Overview-42
Idea: Virtual Counterparts
Virtual World
(Internet, cyberspace)
Pure virtual
objects
Real World
(e.g., every object has a web server)
Overview-43
Ex.: As Artifact Memories

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Updates triggered by
events
Queries from the real
world return memory
content
Sensors generate
events
Overview-44
Magnifying Glass

An object as a web link
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e.g., by displaying a dynamically generated homepage
Contents may depend
on circumstances, e.g.,
context and privileges
possibly mediated by
different name resolvers
HP Cooltown project
Overview-45
CueCat & Its Business Models

Bar code scanner

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Scanners distributed free

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LED based
Attached to computer
via keyboard port
$5-$10 per CueCat
Sends the Web browser
directly to “right” location
when scanning the bar code
of an ad in a magazine
Overview-46
Other Applications

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Physical browsing (physical entity as an icon or URL link
to web pages)
Physical objects as content repositories (by associating
objects with content)
Copy-and-paste in the real world
Objects as communication points (by communicating
content between two persons)
Objects as physical representation of virtual state, mixed
reality, smart environment
Overview-47
Smart Environment, Dumb Object

A context-sensitive cookbook with RFID
RFID
Overview-48
Can be Context-Aware

Properties of the ingredients
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Properties of the kitchen
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Check whether there is enough of an ingredient
Prefer ingredients with earlier best-before date
Check whether required tools and spices are available
Preferences and abilities of the cook
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Prefers Asian dishes
Expert in vegetarian dishes
Overview-49
AT&T Sentient System
Timeline-based context storage
Location tracking
Position monitoring
Overview-50
MIT Oxygen Project
Overview-51
Berkeley’s Wireless Sensor Network

MICA Motes, sensors, and TinyOS:
Overview-52
Other Opportunities
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New digitally enhanced products
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New services (“e-utilities”)
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e.g., cooperating toys, air conditioner, ...
e.g., management of smart devices at home,
management of personal privacy,...
Detailed and timely knowledge of product
location and life cycles, individual and dynamic
prices for goods,...

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e.g., milk bottle reduces its price with its age
e.g., higher taxes if product transported by plane
Overview-54
Outline
The Vision
 The Enablers
 Example Projects
 Summary

Overview-55
New Science from Exploring
Ubicomp

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Theoretical computer science: network security, caching
over slow networks, …
Operating systems: scalable to wristwatches, userextensible O.S.’s, reliable without redundancy, low power
O.S.
User interfaces, hardware and software gestures, twohanded input, pie-menus, unistroke alphabets
Networking, hardware and software: radio, infrared,
mobile protocols, in-building wireless LANs, over varying
bandwidth
Computer architecture, hardware and software: post-itnote computers, low power O.S., multimedia pad
computers
Overview-57
Summary

Ubiquitous computing emphasizes metaphors of
life, interaction with other people, invisibility, and
is leading to new discoveries in computer
science
“Using a computer should be as refreshing as
taking a walk in the woods.”
Overview-58