pervasive computing · @ 2003, d. saha, indian institute of management calcutta (iim-c), india 2...

1@ 2003, D. Saha, Indian Institute of Management Calcutta (IIM-C), India

October 08, 2003Division of IT, Karlstad University

Pervasive Computing:Issues & Challenges

Debashis Saha, Debashis Saha, Ph. D.Ph. D.

MIS & Computer Science GroupIndian Institute of Management (IIM), Calcutta, India

Joka, D. H. Road, Calcutta 700 104, [email protected]



Source Article““Pervasive Computing: A ParadigmPervasive Computing: A Paradigm

for the 21for the 21stst Century Century””

ByDebashis Saha & Amitava Mukherjee,

IEEE Computer Magazine,Vol. 36, No. 3, pp. 25-31, March 2003



Source Book““Networking Infrastructure forNetworking Infrastructure for

Pervasive Computing:Pervasive Computing:Enabling Technologies and SystemsEnabling Technologies and Systems””

ByDebashis Saha,

Amitava Mukherjee &Somprakash Bandyopadhyay

Kluwer Academic Publishers (KAP),Boston, USA, October 2002

ISBN: 1-4020-7429-X, 320 pp, Oct. 2002



Outline� Introduction

� What is “Pervasive” ?

�Evolution of Computing� Personal, Distributed, Web, Mobile, Pervasive …..

�Pervasive Computing Model� PerNet, PerWare, PerApp

�Issues & Challenges� Scalability, Heterogeneity, Perception, etc…….

� Recent Achievements� Research Initiatives

� Conclusion



Introduction

Indian Institute of ManagementIndian Institute of ManagementCalcutta (IIM-C)Calcutta (IIM-C)



What is Pervasive Computing?• An overall infrastructural support to provide

proactively a rich set of computing capabilities andservices to a user (may be a nomad) every timeeverywhere in a transparent, integrated andconvenient way.

• A convenient interface (not only access), through anew class of appliances, to relevant information– with the ability to either take action on it or get acted upon

by it, whenever and wherever necessary.• A tool to quickly, efficiently, and effortlessly help

manage information,– the new currency of the global economy.



We begin with ……………

“the vision”

……….…..of Mark Weiser

The Story of Sal

Ref: Weiser M., “The Computer for the 21st Century”, ScientificAmerican, September, 1991, (reprinted in IEEE Pervasive(reprinted in IEEE PervasiveComputing, Vol. 1, No. 1, pp. 19-25, Jan-Mar 2002).Computing, Vol. 1, No. 1, pp. 19-25, Jan-Mar 2002).



Motivation• To build up computers“that fit the human

environment, instead of forcing humans to entertheir”

• Ultimate goal is to “make using computer asrefreshing as taking a walk in the woods”““The most profound technologies are thoseThe most profound technologies are those

that disappear. They weave themselvesthat disappear. They weave themselvesinto the fabric of everyday life until they areinto the fabric of everyday life until they are

indistinguishable from it.indistinguishable from it.”” – Mark Weiser



Bottomline

“….a new way of thinking about computers in theworld, one that takes into account the naturalhuman environment and allows the computersthemselves to vanish into the background…….”

- Mark Weiser of Xerox PARC (1991).



Objectives• Leverage proliferation of cheap smart devices

with computing resources:• handhelds, micro-ovens, smart cards, displays, cell-phones,

etc.

• Take advantage of the Internet (a global self-adaptive system)

• Utilize resources wherever possible

• Harness mobile cellular infrastructure(terminal mobility)

• Small handheld smart devices



“Smart Devices”



Pervasiveness• Computing will be everywhere: pens, cans, pads,

boards, coffee machines, alarm watches, etc.– Invisible and sublime

• Communication will be everywhere: among alldevices– Wired and/or wireless– Single-hop or multi-hop

• Some of the devices (like traffic lights, ovens, etc.)already have computers incorporated, but withoutthe possibility of communicating between eachother,– which is very important as shown in next example



Intelligent Refrigerator• Take out last can of

milk

• Swipe can’s UPC label,which adds milk toyour shopping list forFriday afternoon

• Make a note that youneed milk for theguests you are havingover this weekend



Reminder to Pager• Friday rolls around

and you have notbought milk

• You are on yourway back fromoffice

• Deadline-basedreminder is sent bythe refrigerator toyour pager



Helpful AutoPC• AutoPC informs

you that you arenow near asupermarket

• Opportunisticreminder: “If it isconvenient, stopto buy milk”



Paradigm Shift PervComp defines a major paradigm shift

from“anytime anywhere” computing

(which is essentially a reactive approach)to

“all-time everywhere” computing(which is a proactive approach for computing).

Simply speaking, it is Simply speaking, it is ““omni-computingomni-computing””



Proactive Computing• Able to read your mind and environment:

– Can dynamically reconfigure to match availableresources

– May suspend/resume on different platforms andlocations

– Can receive active guidance from system– Can do corrections, alternatives on its own– …………..

• Something similar to the Screen Fridge shownnext



Screen Fridge• Screen Fridge provides:– food management,– digital cook book,– TV,– radio,– surveillance camera,– web surfing,– virtual key board,– video messages,– Email,– ……..



Evolution of PerCom

With this introduction, let’s now lookinto ……




Evolutionary Path

(Ref :Satyanarayanan, IEEE Personal Comm., Aug 2001)



Historical Evolution• Personal Computing

– visibly distinguishable from our daily life,• apart from its complex user interface problem

• Distributed Computing– advent of networking, in particular LANs

• Web Computing– World Wide Web (WWW) following the Internet

• Mobile Computing (MobiCom)– cellular mobile technology

• Pervasive Computing (PerCom)



Pervasive ComputingPervasive Computing

Pervasive Middleware

MOBILE SYSTEM

MOBILECOMPUTING

PERVASIVENESSSUPPORT

Pervasive Network

+



IssuesSupport for pervasiveness will come from

interoperability,uneven conditioning,

scalability,smartness, &invisibility,

on top of mobility



PerCom Model




Four Components• Four main parts

– Cheap, low-power computers that include convenientdisplays

• Pervasive Devices– A network to tie them together

• PerNet– Software systems to implement ubiquitous applications

• PerWare– Software systems to implement ubiquitous applications

• PerApp



PerCom Architecture• PerCom architecture can be framed into three broad

areas:– PerNet

• networking,– PerWare

• middleware,– PerApp

• applications

• To implement this architecture, all the three sets oftechnologies must be used judiciously



PerCom Model

Applications

Middlewares

Network (PerNet)

user

user

user

user



Low-power Computers• The first requirement is not so difficult to be

met• Even at the time when Weiser’s paper was written such

devices existed– Today there are mobile devices with processors of 1.8 GHz

(maybe more), RAM of 256 Mb and color displays– Moore’s Law reign supreme

• The devices should be simple and multi-functional

• No complex technologies– Easy to use– May be solved by midlewaresmidlewares



PerNet• The basic idea behind PerCom is to deploy a wide

variety of smart devices throughout our working andliving spaces.

• These devices coordinate with each other using apervasive network, called PerNet– to provide users with universal and immediate access to

information and support users in completing their tasks.• Fortunately, this networking infrastructure, which is

necessary to realize the vision of PerCom, isincreasingly becoming a reality– See the next slide



Network ViewWIRED BACKBOME NETWORK

WIRED over WIRELESS NETWORK

PERVASIVE NETWORK

PERVASIVE COMPUTING SYSTEM

WIRELESS ACCESS

PERVASIVENESS MANAGEMENT

MIDDLEWARE SUPPORT



Potential Structure of PerNet• PerNet may consist of:– a core of backbone (probably wired) and– a shell of access (invariably wireless).• From the current pattern of network

deployment, it is emerging as the most naturalarchitecture

– Popularly known as “last/first mile (hop) wireless”architecture, also called it as “wireless over wired”.

– The last/first mile of access has to be wirelessbecause of the requirement to support mobility



Structure (contd.)

Backbone(core)

Access (shell)

user

user

user



Structure (contd.)• The backbone may be either wired (say, optical) or

wireless (say, satellite).• A popular implementation of PervNet structure could

be “cellular over optical”– Since optical transmission is the preferred technology for

high speed high bandwidth backbone and– single hop cellular is the common access technology,

• It indicates that these two technologies, namely opticaland cellular, are the dominant ones from the point ofboth penetration rate and technological maturity



Existing Building Blocks• The Internet

– IPv4, IPv6, Mobile IPv6• provides some of the links in which a distributed federation

forms

• Mobile Wireless Networks– Cellular technology– MANET, sensor-net

• Smart sensor nodes will form ad hoc networks dynamically

• WDM Optical Networks– GMPLS

• Fiber-optic technology can be considered to meeting the hugedemand in future backbone networks

• Satellite Networks



PerWare• A shell of middleware

– essential to interface between the PerNet kernel and theend-user applications running on pervasive devices.

• Responsible for keeping the users immersed in thePerCom space– and for mediating all interactions with the PerNet kernel

on behalf of the user.

• Mostly be a bundle of firmwares and/or softwares– executing in either client-server or peer-to-peer mode.



Issues




Why Difficult?When applied to PerCom, existing approaches to

conventional distributed computing are insufficient:– Due to its dynamic and distributed nature

• applications need to be able to acquire any resource they need atany time,

– so that they can continuously provide their services in a highly dynamicenvironment.

– Need of a common system platform,• allowing applications to be run across the range of devices and to

be automatically distributed, installed and configured.

– Data and functionality need to be kept separate,• so that they can evolve gracefully in the global PervComp

infrastructure.



Global Dimension• PerCom aims for a world in which every object, every

building, and every body becomes part of a networkservice– That is PerNet

• PerCom space is a combination of mobile andstationary devices– that draw on powerful services embedded in the underlying

PerNet to achieve users’ tasks.

• The result is a giant ad-hoc mobile distributed systemgiant ad-hoc mobile distributed system,– with tens of thousands of devices and services coming in

and going out.



Networking is the key• The devices are available• What is missing is the right network

architecture that• Incorporates pervasive computing devices into

the system as information managers, and• Introduces an abstraction to describe context-

sensitive information– i.e., addresses the information management

problem



Role of PerWare• PerNet will pass onto PerWare the responsibilities it

can not provide to get the required functionalities• PerWare has to absorb the differences and emulate

the missing capabilities wherever needed• New systems that have to deal with the diversity of

inputs from the user• New middleware ideas are required

– that does not assume a relatively fixed configuration ofhardware and software



Classification of Issues• Integration

– Heterogeneity

• Scalability– Global

• Context awareness– or perception

• Context management– or smartness

• Invisibility– Self-tuning and anticipation

PerNet Level

PerWare Level



Challenges




Strategy• We have identified the issues and classified

them under broad headings• We have tried to understand at what level these

issues are to be addressed• Now let us find out the potential solution

strategies and the challenges therein– Remember, we have seen only the tip of the

iceberg– More research is needed to understand it

compeletly



Recap of Issues• Integration

– Heterogeneity

• Scalability– Global

• Context awareness– or perception

• Context management– or smartness

• Invisibility– Self-tuning and anticipation

PerNet Level

PerWare Level



Potential Solutions• Adaptation

– Possible three strategies

• Smart Spaces– Embedded technology

• Scalability– Localization

• Invisibility– Minimal user distraction

• Integration– Seamless interoperability



Perception• Implementing perception introduces significant

complications:– location monitoring, uncertainty modeling, real-time

information processing, and merging data from multipleand possibly disagreeing sensors.

• information that defines context awareness must be accurate;– otherwise, it can confuse or intrude on the user experience.

• Examples:– ComMotion under development at the MIT Media Lab

• www.media.mit.edu/~nmarmas/comMotion.html– Microsoft Research is investigating Radar

• an in-building location-aware system.



Smartness• Smartness involves accurate sensing (input) followed

by intelligent control or action (output) between twoworlds– namely machine and human

• E.g., a pervasive computing system that automaticallyadjusts heating, cooling, and lighting levels in a roomdepending on an occupant’s electronic profile must have– some form of perception to track the person and also– some form of control to adjust the ventilation and lighting

systems



Anticipatory Self-tuning• To meet user expectations continuously, the

environment and the objects in it must be able to– tune themselves without distracting users at a conscious

level.

• A system that requires minimal human interventionoffers a reasonable approximation of invisibility.

• Humans can intervene to tune smart environments when theyfail to meet user expectations automatically.– Such intervention might also be part of a continuous learning cycle for

the environment.– AI has some role to play here!



Adaptation• Adaptation is necessary whenever– there is a significant mismatch between the supply

and demand of a resource• The resource may be– wireless network bandwidth,– energy,– computing cycles,– memory,– and so on



Three Strategies• Client guides applications in changing their behavior

– so that they use less of a scarce resource• This change usually reduces the user-perceived quality, or

fidelity, of an application

• Client asks the environment to guarantee a certainlevel of a resource– This is the approach typically used by reservation-based

quality of service (QoS) systems• From the viewpoint of the client, this effectively increases the

supply of a scarce resource to meet the client’s demand

• Environment suggests a corrective action to the user• If the user acts on this suggestion, it is likely (but not certain)

that resource supply will become adequate to meet demand



Immediate Questions• How does a client choose between adaptation

strategies?• What factors should a good decision procedure

take into account?• How should different factors be weighted?• What role, if any, should the user play in

making this decision?• How can smooth and seamless transitions

between strategies be ensured as a usermoves?



Smart Spaces• By embedding computing infrastructure in building

infrastructure, a smart space brings together twoworlds

• Physical & Logical

• Fusion of these worlds enables sensing and controlof one world by the other

• E.g., automatic adjustment of heating, cooling, and lighting levels ina room based on an occupant’s electronic profile

• Influence in the other direction is also possible• software on a user’s computer may behave differently depending on

where the user is currently located



• Complete disappearance of pervasivecomputing technology from a user’sconsciousness

• In practice, a reasonable approximation to thisideal is minimal user distraction

• If an environment continuously meets userexpectations and rarely presents him withsurprises, it allows him to interact almost at asubconscious level

Invisibility



Localized Scalability• Scalability, so far, has ignored physical distance

• a Web server or file server should handle as many clients as possible,– regardless of whether they are located next door or across the

country

• In PerNet, the density of interactions has to fall offas one moves away;

• otherwise, both the user and his computing system will beoverwhelmed by distant interactions that are of little relevance

• Although a mobile user far from home will stillgenerate some distant interactions with sites relevantto him, the preponderance of his/her interactionswill be local



Current Status




Research Initiatives• ParcTab project of Xerox :: Mark Weiser• Project Aura at Carnegie Mellon University (CMU)

(http://www-2.cs.cmu.edu/~aura/)• Endeavour Project in the University of California at

Berkeley (http://endeavour.cs.berkeley.edu/)• Project Oxygen of MIT

(http://www.oxygen.lcs.mit.edu/)• Portolano Project of the University of Washington

(http://portolano.cs.washington.edu/).• Sentient computing at AT&T Laboratories, Cambridge,

UK (http://www.cam-orl.co.uk/spirit/)



Initiatives (contd.)• CoolTown project of HP Laboratory

(http://www.cooltown.com),• EasyLiving project of the Vision Group at Microsoft

Research (http://research.microsoft.com/easyliving/),• pvc@IBM (http://www-3.ibm.com/pvc/),• eBiquity Group, at University of Maryland at

Baltimore County (http://research.ebiquity.org/),• one.world at University of Washington

(http://one.cs.washington.edu/)• And many more ……….



Aura“distraction free ubiquitous computingdistraction free ubiquitous computing”

• It emphasizes PerWare and PerApp design• It aims to implement a large scale computing system

demonstrating a “personal information aura”– that spans wearable, handheld, desktop, and infrastructure

computers.• A large umbrella project with sub-areas like:

– Darwin: an intelligent network at Aura’s core.– Coda: a distributed file management system that supports

nomadic file access, and– Odyssey: operating system support for resource adaptation.



Endeavour• A planet-scale, self-organizing, and adaptive

“information utility.”• Components flow through the infrastructure, shape

themselves to adapt to their usage, and cooperate ontasks– over a PerNet

• Key innovative technological capability– support for fluid software

• The system can compose itself from preexisting hardwareand software components to satisfy a service request– while advertising the services it can provide to others.



Oxygen• Computation will be freely available everywhere

– like oxygen in the air we breathe.

• The project rests on an infrastructure of mobile andstationary devices– connected by a self-configuring network.

• It is focusing on eight environment-enablingtechnologies.

• Its emphasis is on understanding “what turns anotherwise dormant environment into an empoweredone to which users shift parts of their tasks”.



Portolano• An infrastructure based on mobile agents

– that interact with applications and users.• It emphasizes invisible, intent-based computing,

– which infers users’ intentions via their actions in the environmentand their interactions with everyday objects.

• Project devices are highly optimized to particular tasks– so that they blend into the world and require little technical

knowledge on the user’s part.• Data-centric routing automatically migrates data among

applications on the user’s behalf.– Data thus becomes “smart,” and serves as an interaction

mechanism within the environment.



Conclusion




Imminent Research Issues• Scalability

• All pervasive IP

• Signaling overhead

• Location and mobility awareness

• Context Awareness & Sensitiveness

• Sophisticated resource management

• Privacy, Security and Manageability



Near FutureInternational Data Corp. (IDC) has predicted that,

by the end of 2003, the number of pervasive devices willexceed the estimated number of people (6 billion)worldwide.

Specifically, there will be more than• 300 million PDAs,• 2 billion consumer electronic devices,

– such as wireless phones, pagers and set top boxes, and• 5 billion additional everyday devices,

– such as vending machines, refrigerators, and washingmachines,

all embedded with chips connected to the PerNet !!!



Seamless Integration• The biggest surprise is how simple and basic all the

component technologies are:• The hardware technologies: laptops, handhelds, wireless

communication, software-controlled appliances, room cameras, etc.• The component software technologies: location tracking, face

recognition, speech recognition, online calendars, and so on

• The answer lies in the fact that the whole is muchgreater than the sum of its parts

• In other words, the real research is in the seamlessintegration of component technologies into a system

• The difficult problems lie in architecture, componentsynthesis, and system-level engineering



Conclusion• PerCom is the crucible in which many disjoint areas of

research are fused– Capabilities from different areas will need to be integrated

with the kinds of computer systems capabilities• PerNet will be a fertile source of challenging research

problems for many years to come– Solving these problems will broaden the discourse on some

topics, and revisit long-standing design assumptions• The early decades of the 21st century will be a period

of excitement and ferment,– as new hardware technologies converge with research

progress on the many fundamental problems



Any Question ?•• Please feel free to write to me forPlease feel free to write to me for

any doubt:any doubt:

[email protected]@iimcal.ac.in



Other References• M. Satyanarayanan, “Pervasive Computing: Vision and

Challenges”, IEEE Personal Communications, Aug 2001, pp10-17

• Special inaugural issue on Reaching for Weiser’s Vision, IEEEPervasive Computing, Vol. 1, No. 1, Jan-Mar 2002.

• Archan Misra, Subir Das, Anthony Mcauley and Sajal Das,“Autoconfiguration, Registration and Mobility Managementfor Pervasive Computing”, IEEE Personal Communications,Aug 2001, pp 24-31

• C. Perkins, “IP Mobility Support,” IETF RFC 2002, Oct. 1996• Charles E. Perkins, “Mobile IP”, IEEE Communications

Magazine, May 1997, pp 84-99

pervasive computing · @ 2003, d. saha, indian institute of management calcutta (iim-c), india 2...

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