The Computer for the 21st Century

Mark WeiserScientific American, September 1991

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Introduction

“The most profound technologies are those that disappear. They weave themselves into the

fabric of everyday life until they are indistinguishable from it.”

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Introduction

Mark Weiser often referred to as the father of ubiquitous computing

Coined the term in 1988

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First Information Technology

Writing as an example,Ability to represent spoken languageLong term storage of informationUbiquitous in industrialized nations

Where is it?Books, magazines, street signs, billboards, candy wrappers

Constant background presence of this “literary technology” does not require active attention

Information to be transmitted is ready at a glance

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Computers Today (1998)

“Approachable only through complex jargon that has nothing to do with the task for which people use

computers … analogous to the period when scribes had to know as much about making ink or baking

clay as they did about writing”

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Computers Today (1998)

Not just a user interface problem

Need a new way of thinking about computers

Take into account the human worldVanish into the background

Disappearance due to human psychology not technology

Compiling, tacit dimension, visual invariants, horizon, ready-to-hand, periphery

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Ubiquitous Computing

Ubiquitous Computing ≠ Virtual RealityMakes a world inside the computerExcludes desks, office, trees, weather

Embodied VirtualityBringing computer-readable data into the physical world

http://www.virtusphere.com/

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How Do Technologies Disappear?

LocationComputer must know where it isAdapt behavior

ScaleSuited for a particular task

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Artifacts

TabsInch-scale machinesInterconnectedTake on function that computers don’t

Active badge

PadsFoot-scale machinesIntended to be “scrap computers”

BoardsYard-scale machinesVideo screens, white boards, flip charts, bulletin boards, electronic bookcase

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Technology Requirements

Technology for ubiquitous computing must be

CheapLow power computer that include convenient displaysSoftware for applications and a network that ties everything together

Social issuesPrivacy

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Conclusion

Ubiquitous computers will help overcome information overload

Change viewpoint Move computers in human environmentMake interaction more enjoyable

“There is more information available at our fingertips during a walk in the woods than in any computer system, yet people fine a walk

among trees relaxing and computers frustrating.”

The Coming of Age of Calm Technology

Mark Weiser and John Seely BrownBeyond Calculation (Book), 1997

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Introduction

“The important waves of technological change are those that fundamentally alter the place of

technology in our lives. What matters is not technology itself, but its relationship to us.”

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Introduction

Two great trends over the last 50 yearsMainframePC

Internet carrying us through an era of distributed computing

Bridge to ubiquitous computing

The Major Trends in Computing

Mainframe Many people share a computer

Personal Computer One computer, one person

Internet – Distributed Computing … transitions to …

Ubiquitous Computing Many computers share each of us

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UC ERA

Phase 3 – UC ERA2005 – 2030Lots of computers sharing each of us

Characterized by the connection of things in the world with computation

M. Weiser. “Building Invisible Interfaces," UIST, 1994.

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Harbingers of the UC Era

Easy to find 40 µC in a middle-class home in the US

Alarm clocksMicrowaveTV remote controlToysMany more

Do not qualify as UCMostly used one at a timeMasquerading as old-style devices

Tie devices to internetConnect millions of information sources with hundreds of information delivery systems in your house

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Calm Technology

Most potentially interesting, challenging changed implied by ubiquitous computing is a focus on calm

Computers are all aroundStay out of the wayDesigned so people being shared by the computers remain serene and in control

Difference will be in how they engage our attention

Moves between center and periphery of our attention

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The Periphery

Attuned to without attending to explicitlyWhen driving attention centered on road, radio, passenger, but not noise of the engineUnusual noise noticed immediately, and could quickly attend to it

Calm technology move easily from periphery to center of attention and back

Informing without burdeningAble to handle more information (then if everything at center)User takes control

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Examples of Calm Technology

Inner Office WindowsEnhances peripheral reach and locatedness

Extends periphery by creating two way channel for clues about environment

Connect with those outside the office

Illustrate fundamental property of motion between center and periphery

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Examples of Calm Technology

Dangling String8 foot piece of plastic spaghetti that hangs from small electric motor mounted on ceilingConnected to nearby Ethernet cable so that each bit of information that goes past causes tiny twitch of the motor

Provides background of data weatherBusy network – whirling stringQuite network – small twitch

Placed in unused corner of a hallwayNew center of attention by being uniqueBecomes peripheral as gentle movement becomes backgroundString seen and hear and increases peripheral attunement

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Conclusion

Contradictory statementFrequent complain of information overloadMore information could be encalming

Designing in the era of ubiquitous computingTo become attuned to more information, need to attend to it lessTake into account center and periphery to achieve increased sense of locatedness

Pervasive Computing : Visions and Challenges

M. SatyanarayananIEEE Personal Communications, August 2001

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Introduction

Technology needed to implement Wiesernot available in 1991

What about 2001?Many viable commercial products –handheld, wearable, wireless computingMany research projects target pervasive computing

Challenges in research posed by emerging field of pervasive computing

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Related Fields

Pervasive computing a major evolutionary step

Two predecessors, distributed systems and mobile computingSome problems correlatedSome problems have no obvious mapping to existing problems

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Related Fields

Distributed Computing1970-1990s created conceptual framework and algorithmic base

Remote CommunicationProtocol layering, remote procedure call, use of timeouts, use of end-to-end arguments in placement of functionality

Fault ToleranceAtomic transactions, distributed and nested transaction, two-phase commit

High AvailabilityOptimistic and pessimistic replica control, mirrored execution, optimistic recovery

Remote Information AccessCaching, function shipping, distributed file systems, and distributed databases

SecurityEncryption-based mutual authentication and privacy

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Related Fields

Mobile ComputingAppearance of full-function laptops and wireless LANs in early 1990sConfront problems that arise in building a distributed system with mobile clients

New constraints forced development of specialized techniques

Unpredictable variation in network qualityLowered trust and robustness of mobile elementsLimitations on local resources imposed by weight and size constraintsConcern for battery consumption

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Related Fields

Mobile Computing (continued)

Mobile networkingMobile IP, ad hoc protocols, improving TP performance in wireless networks

Mobile information access Disconnected operation, bandwidth-adaptive file access, selective control of data consistency

Support for adaptive applicationsTranscoding by proxies, adaptive resource management

System level energy saving techniquesEnergy-aware adaptation, variable-speed processor scheduling, energy-sensitive memory management

Location sensitivityLocation sensing, location-aware behavior

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Related Fields

Research problems in pervasive computing relate to those in mobile computing and distributive systems

New problems encountered as one moves from left to rightIncrease in complexity is multiplicative rather than additive

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Pervasive Computing

Computing environment saturated with computing and communication capability

Gracefully integrated, technology disappears

Motion integral part of everyday lifeTechnology must support mobility

Research agenda for pervasive computing

Subsumes mobile computingIncludes additional

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Additional Pervasive Computing Research Thrusts

Effective use of smart spacesEnclosed meeting rooms, corridors, courtyardsEmbedding computing infrastructure into building infrastructuresFusion enables sensing and control of one world by the other

InvisibilityComplete disappearance of pervasive computing technology from user’s consciousnessEnvironment meets user expectation and rarely presents surprisesAllows almost subconscious interaction

Localized scalabilityIntensity of interaction between user’s personal computing space and surroundingsSevere bandwidth, energy, and distraction implications for wireless mobile user

Masking uneven conditioningHuge differences in “smartness” of different environments for decadesJarring to user, distracts from goal of making technology invisiblePersonal computing space needs to compensate for “dumb” environments

Examples Scenarios

Convey the “look and feel” of pervasive worldDeliberately chosen scenarios that appear feasible in just a few years

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Scenario 1

Jane at Gate 23 in Pittsburg airport waiting for connecting flight

Edited large documents, wants to use wireless connection to email themBandwidth bad, many other passengers at Gate 22 and 23 surfing web

Aura realizes Jane can’t send documents before flight departs

Consult airport network realizes bandwidth excellent at Gate 15Dialog box pops up suggesting move to other gateAsks Jane to prioritize so most critical sent firstAura inform Jane when close to don, she can start walking back to gate

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Scenario 2

Fred frantically preparing for a meeting10 minute walk across campusNot finished, download to palm and makes voice command changes

Aura infers what Fred is doing from calendar and campus location tracking service

Aura downloads presentation to projection computer and warms up projectorDuring meeting Fred about to display slide with highly sensitive budget informationAura senses this may be a mistake from room’s face detection and recognition capabilityWarns Fred, he realizes mistake and moves on

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Missing Capabilities

Key ideas needed in pervasive computing

ProactivityJane able to send email because Aura had foresight to estimate how long process would takeImportant to combine knowledge from different levels of system

Self-tuningMove execution from desktop to handheld device to projection computer, different input devicesAutomatically adjust behavior to fit circumstances

Why still science fiction?The whole is function greater than the sum of its partsReal research in seamless integration of component technologiesDifficulty lies in architecture component synthesis and system-level engineering

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Drilling Down

What does road ahead look like?Convey impressionistic pictureSampling of problem space

Assume user immersed in personal computing space

Accompanies them everywhereMediates all interactionsLikely a body-worn or handheld computer which serves as “client”

Research Problems

User IntentMust track user intent or will impossible to determine which system actions will help rather than hinder user

User watching video over network connection whose bandwidth suddenly drops

Reduce fidelity of video?Pause briefly to find another connection?Advise user task can no longer be accomplished?

Systems currently poor at capturing and exploiting user intent

Generic applications don’t know what user is trying to doWhat about Microsoft’s paperclip?

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Research Problems

Cyber ForagingMobile devices smaller, lighter, and have longer battery life

Ever growing expectations for more computing and data manipulation

Dynamically augment computing resources of wireless mobile computer by exploiting wired hardware infrastructure

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Research Problems

Adaptation StrategySignificant mismatch between supply and demand of a resourceBandwidth, energy, computing cycles, memory, etc.

Client guide application into changing their behavior

Use less of scare resource

Client ask environment to guarantee certain level of resource

Reservation based system

Client suggest corrective actionJane moved to different gate where resource supply likely (not guaranteed) to meet demand

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Research Problems

High-level energy managementProactive and self-tuning techniques increase energy demandBattery technology and low-power circuit design cannot by themselves reconcile opposing constraintsHigher levels of system must be involved

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Research Problems

Client ThicknessHow powerful does a mobile client need to be for a pervasive computing environmentThick – powerful clientThin – minimal client

Minimum acceptable thickness determined by worst case environmental conditions that it must run satisfactory

Client recognize key assumption not being met, alter user with intelligible message

Move to nearby location

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Research Problems

Context awarenessCognizant of user’s state and surroundings to be minimally intrusiveModify behavior based on informationHuman assistant given context, able to make decisions in proactive fashion, anticipating user needs

Can pervasive system emulate human assistantKey is to obtain information neededPhysical location – orientation, people nearbyEmotional state – angry, distraught, calmPersonal history and daily behavioral patternsComputing space – calendars, address books, contact lists, to-do lists

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Research Problems

Balancing proactivity and transparencyProactive system can annoy user and defeat goal of invisibility

How to strike proper balance?Self-tuningNeed and tolerance based on level of expertise on a task and familiarity with environmentSystem can infer by observing user behavior and context

Transparency asking user before action taken

User patience modelInternal model to predict user response

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Research Problems

Privacy and trustMechanisms for location tracking, smart spaces, and use of surrogates monitor user actions continuouslyExploiting information needed to proactivity and self-tuning

Unless information strictly controlled, could be used unsavory used from span to blackmail

Deter users

ImplicationReliance on infrastructure means user trusts that infrastructureInfrastructure needs to be confident of user’s identity and authorization level before responding to request

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Research Problems

Impact on LayeringRecurring theme is the merging of information from diverse layers to produce effective response

Layering cleaning separates abstraction from implementation

Standardization for modular componentsHow to decompose system is nontrivial

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Conclusion

Pervasive computing fertile source of challenging research problems

Revisit long standing assumptions

Address research challenges in areas outside of computer systems

Human computer interaction, software agents, expert systems, AI

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“Like the Frontier of the American West in the early 19th century, pervasive computing offers new beginnings for the adventurous and the restless – a rich open space where the rules have yet to be written and the borders yet to be

drawn.”