Mobile, … Pervasive Computing
Prabhaker Mateti
Networked Computing
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Send-Receive Message Passing paradigm
Independent computer systems as Nodes
Aware of other nodes and networks of nodes
Loss of messages, a serious concern
Ordered delivery, a serious concern
A snapshot of “global state” is not possible
– global time stamps not available
– define a “happened before” relation
• Client-Server computing
• Master-Slave computing
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Distributed Computing
• Def: Computation based on send-receive of
messages without shared memory state but
with synergy.
– Networked computing with “synergy”
– Many variations loosen up the definition.
• Peer-to-Peer computing
• Spreading out and shrinking back on the
network
• “Distributed Shared Memory”
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Distributed Computing Software
• Cluster Computing
• Grid Computing
• PVM (Parallel Virtual Machine)
– in spite of the name, a distributed computing paradigm
– http://www.csm.ornl.gov/pvm/
• MPI (Message Passing Interface)
– MPI-2.2 approved Sep 2009.
– http://www.mpi-forum.org/
• Condor
– e.g., use idle machines
– http://www.cs.wisc.edu/condor/
• OpenMP is for parallel computing http://openmp.org/
• Distributed OS exist but not gained a foothold.
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Parallel Computing
• Def: Computation based on shared memory state and
with synergy.
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Many variations loosen up the definition.
often used loosely
“Strongly coupled” nodes
Mutual exclusion a serious concern
MIMD, SIMD, …
Parallel Fortran, … languages
Scientific computing
Multi-Core CPUs
Cellular Computing: PlayStaion3
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Ubiquitous Computing
• Mainframe: Many people share one computer.
• Personal Computer: One person with one
computer.
• Ubiquitous Computing: Many computers serve
each person.
• “the age of calm technology, when technology
recedes into the background of our lives.”
• roughly the opposite of virtual reality
• From: Mark Weiser, sandbox.xerox.com/
ubicomp/, 1996
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Ubiquitous Computing Scenario
• Provide hundreds of wireless computing devices
per person per office, of all scales
– from 1" displays to wall sized.
– This may require new work in operating systems, user
interfaces, networks, wireless, displays, …
• This is different from PDA's, dynabooks, or
information at your fingertips.
• It is invisible, everywhere computing that does
not live on a personal device of any sort, but is in
the woodwork everywhere.
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Ubiquitous Computing Scenario
• small, inexpensive, robust networked processing devices
• distributed at all scales throughout everyday life and
generally turned to distinctly common-place ends.
• For example, a domestic ubiquitous computing
environment might interconnect lighting and
environmental controls with personal biometric monitors
woven into clothing so that illumination and heating
conditions in a room might be modulated, continuously and
imperceptibly.
• Another common scenario posits refrigerators "aware" of
their suitably tagged contents, able to both plan a variety of
menus from the food actually on hand, and warn users of
stale or spoiled food.
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Ubiquitous Computing Definitions
• "machines that fit the human environment
instead of forcing humans to enter theirs.“
• “Computing without computers, where
information processing has diffused into
everyday life, and virtually disappeared from
view.” -- Adam Greenfield, Everyware: The
Dawning Age of Ubiquitous Computing, 2006
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Weiser’s Ubiquitous Devices 1996
• Tabs: wearable centimeter sized devices
• Pads: hand-held decimeter-sized devices
• Boards: meter sized interactive display
devices.
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More Ubiquitous Devices
• “like pigment in the wall paint”
• Dust: miniaturized devices can be without visual
output displays, e.g., Micro Electro-Mechanical
Systems (MEMS), ranging from nanometres to
millimetres.
• Skin: fabrics based upon light emitting and
conductive polymers, or organic computer
devices
• Clay: ensembles of MEMS can be formed into
arbitrary three dimensional shapes as artifacts
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MicroSoft “Surface”
Download the MS Surface 2.0 SDK
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Typical 2011 Cloud Computing
• File storage accessible via Internet to PCs, …,
mobile devices
– DropBox, SugarSync, iCloud, SkyDrive, …
• Shipping off a well-defined computation and
data to an outsource provider
– Google Apps
– Amazon Elastic Compute Cloud (EC2)
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Cloud computing
http://en.wikipedia.org/wiki/File:Cloud_computing.svg
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Cloud Computing
• “Cloud computing provides computation,
software, data access, and storage services
that do not require end-user knowledge of the
physical location and configuration of the
system that delivers the services.”
• Cloud computing characteristics: Agility,
Reduced Cost, Device And Location
Independence, On-demand Scalability And
Performance
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Pervasive Computing
• Invisible Computing Everywhere: A world in
which virtually every object has processing
power with (wireless or wired) connections to
a global network.
• Devices
– RFID (radio frequency identification) tags
– Active badges worn as ID cards.
– Memory buttons that store information.
• Contextual computing
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Mateti
Pervasive Computing
• Internet as the start of a pervasive computing system.
• “Pervasive computing envisions environments richly
lathered with computation, communication and
networked devices, mobile users interacting with their
environment using speech and vision, with secure
access to personal or public data. Pervasive computing
environments will not simply be stand-alone vehicles
for number crunching, rather they will immerse their
users in a triad of invisible computation,
communication and devices, working in concert to
satisfy user requirements according to the facilities
available in the environment.” -http://groups.csail.mit.edu/cag/classes/6.898/
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Applications of Pervasive Computing
• Smart Homes
– appliances communicate with each other
– television, lighting, heating and home security
• Smart Cars
– controlling the radio, transmission, remembering your seat position, adjusting
the temperature, making the suspension work better, helping you see in the
dark, and warning when tire pressure is low.
• Smart “Things”
– Barcodes, Auto Identification (Auto-ID)
– RFID tollbooth systems, such as E-Z Pass.
• Large-scale pervasive computing
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Smart Schools
Intelligent Elder- Care
Smart Offices
Digital Cities
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Mateti
Goals of Project Oxygen
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pervasive—it must be everywhere, with every portal reaching into the same
information base;
embedded—it must live in our world, sensing and affecting it;
nomadic—it must allow users and computations to move around freely, according
to their needs;
adaptable—it must provide flexibility and spontaneity, in response to changes in
user requirements and operating conditions;
powerful, yet efficient—it must free itself from constraints imposed by bounded
hardware resources, addressing instead system constraints imposed by user
demands and available power or communication bandwidth;
intentional—it must enable people to name services and software objects by
intent, for example, "the nearest printer," as opposed to by address;
eternal—it must never shut down or reboot; components may come and go in
response to demand, errors, and upgrades, but Oxygen as a whole must be
available all the time.
http://oxygen.lcs.mit.edu/Overview.html
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Conferences
• http://www.ubicomp.org/ UbiComp 2011,
13th International Conference, Sep 2011.
• http://www.percom.org/ PerCom 2012, 10th
IEEE Pervasive Computing and Communication
(PerCom) conference, Nov 2011
• http://distributedcomputing.info/conferences.
html Many.
• http://www.sigmobile.org/mobicom/
MobiCom 2011, Sep 2011
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References
• M Satyanarayanan, Pervasive computing: Vision and
challenges, IEE Personal Communications, IEEE, 2001,
ieeexplore.ieee.org
• Frank Stajano, “Security Issues in Ubiquitous
Computing”, HANDBOOK OF AMBIENT INTELLIGENCE
AND SMART ENVIRONMENTS, 2010, Part III, 281-314
• Jin Nakazawa, et al., A Description Language for
Universal Understandings of Heterogeneous Services in
Pervasive Computing, 2010 IEEE International
Conference on Sensor Networks, Ubiquitous, and
Trustworthy Computing.
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