introduction to pervasive computing

Introduction to Pervasive Computing

By H. Momeni Computer Engineering Department Iran University of Science and Technology

December 2006

Agenda• History and Evolution• Vision• Pervasive Computing Features• System View and Support• Framework• Applications• Challenges

December 2006Iran University of Science and TechnologyOf 43


Remote communication

Fault tolerance

High Availability

Remote information access

Distributed security

Distributed Systems

(mid-1970s)

Mobile networking

Mobile information access

Adaptive applications

Energy-aware systems

Location sensitivity

Mobile Computing(early 1990s)

Smart spaces

Invisibility

Localized scalability

Uneven conditioning

Pervasive Computing

(2000)

History and Evolution



Comparison



Pervasive Technologies• Ubiquitous Computing (Mark Weiser, Xerox PARC

1990)• Calm Computing (John Brown, Xerox PARC 1996)• Tangible Computing (Ishii, 1997)• Universal Computing (James Landay, Berkeley

1998)• Invisible Computing (G. Barriello, UoWashington

1999)• Context Based Computing (Berkeley/IBM 1999)



Pervasive Technologies cont’d• Hidden Computing (Toshiba 1999)• Pervasive Computing (Academia, IBM 1999, SAP

2000)• Everyday Computing (Georgia Tech, 2000)• Sentient Computing (AT&T, 2002)• Autonomous Computing (IBM, 2002)• Amorphous Computing (DARPA, 2002)• Spray Computing (Zambonelli, 2003)



Vision“The most profound technologies are those

that disappear. They weave themselves into the fabric of everyday life until they are indistinguishable from it”. [1991]



Computer Evolution• Weiser’s idea was a vision too far ahead of its time• The hardware technology did not exit• After a decade hardware progress, PerCom are viable



The State of the Art in Pervasive Computing• The term “Pervasive Computing” emerged from

research at IBM during 1996 – 97

• vision: computing services available anytime, anywhere and on demand

• Mark Weiser at Xerox PARC was leading research labeled as “Ubiquitous Computing in 1991



The State of the Art… cont’d• UbiComp’s initial focus was not on making

infrastructure available everywhere

• UbiComp’ initial focus was on user centric

• PerCom’s initiative to exploit the existing wide scale deployment of computing technology

• UbiComp’s initiatives were to effectively make this complex mass of technology transparent to the human user’s



Research Areas in Pervasive Computing• mobile computing• wireless networking• embedded computing• human computer interaction (HCI)• Context awareness with sensor technology

other terms tend to be an overlap of these five themes

Wearable Computing=Mobile Computing+Embedded Computing+HCI

Nomadic Computing=Mobile Computing+wireless networking



A Pervasive Computing Model• five-layered model (from the perspective of the

human)– physical layer– Perceptive layer

• Composed of sensor (input for physical layer) and actuator (output for physical layer)

– Analog/Digital conversion layer• Converting between analog and digital signals

– Computational layer– Communicational Layer

Primary functions• coordination of environments(Os, protocol)

Secondary functions•actual applications within environment



Pervasive computing Features• A Device : portal into an application-data space

• Computing environment : an information-enhanced physical space

• Connected devices provide services without user’s interventions by using sensed data in physical space.

• Providing services for users anytime, anywhere by any devices



System view of pervasive computing



Pervasiveness Support• Effective Use of smart spaces• Invisibility• Localized scalability• Masking uneven conditioning



Effective use of Smart Spaces• Embedding computing infrastructure in

building infra.• Smart spaces brings together two world that

have been disjoint until now• The fusion of these worlds enables sensing and

control one of world by the other

Smart coffee cup

Automatic meeting transcription



Invisibility• Weiser’s ideal: complete disappearance of

technology• minimal user distraction• system meets user expectations continuously• proactivity may sometimes be valuable



Localized Scalability• With increase of complexity of smart spaces,

number of interactions between user’s computer and environment will be increased.

• This has severe bandwidth, energy for a wireless mobile user

• Scalability is a critical problem in PerCom• Traditional scalability has ignored physical

distance (web server)



Masking Uneven Conditioning• There will persist huge differences in the

smartness of different environments• This large dynamic range of smartness can

reduce invisibility of PerCom to users• Solving problem

– Reduce the variability (to compensate space, dumb environment)



Pervasive Computing Framework



Pervasive Devices• Traditional input/output devices

– Keyboard, speaker, light-emitting diode• Wireless mobile devices

– Pager, PDA, cell phone, palmtop, Laptop• Smart devices

– Intelligent appliance, floor tiles with embedded sensor, biosensors



Pervasive Networking• IEEE 802.11• Bluetooth• Internet



Pervasive middleware• Interface between the network kernel and the

end-user applications running on pervasive devices

• keep users immersed in the pervasive computing space

• Consist mostly firmware and software bundles executing in client-server or Peer to peer



User interface and application• User interface

– Web browser– Micro browser

• Pervasive applications– more environment-centric than either web-based

or mobile computing applications



Applications



Daily Life Application• Smart Home



Public Service Application• Healthcare: Embedded Sensor networking for

patient monitoring



Transportation Application• Smart Cars



Environment Applications• Environmental Monitoring



National Defense Applications• Surveillance Platform



Industrial Business Applications

• Supply Chain Management



Challenges• User intent• Cyber Foraging• Adaptability• High Level Energy Management• Context awareness• Trust • Privacy• Security



User Intent• PerCom system must track user intent for

Proactivity• Challenges:

– Can user intent be inferred?– How is it handled in dynamic interactions?– When and how is it updated?– Will it hurt usability and performance unacceptably?



Cyber Foraging• The need to make mobile devices smaller, lighter

and longer battery life, reduce computing capabilities

• Solution:– Exploiting wired hardware infrastructure in a neighborhood

that it play surrogate role– The mobile computer ships the computation to the

surrogate• Challenges:

– Discover the presence of surrogate – Load balancing – Minimal delay



Adaptability• Significant mismatch between the supply and

demand of a resource • New user’s requirements • Change Requirements

• Challenge– Reduce human intervention– Configuration– Run time Reconfiguration



High Level Energy Management• Proactivity and self-tuning increase the energy

demand of software on mobile devices• The attempts to make such devices lighter and

smaller, reduce the battery capacity• The higher level of must be involved to save

energy.– Energy aware memory management– Energy aware adaptation

• Challenges– Impact of invisibility– Exploit of knowledge of user intent

December 2006

Iran University of Science and TechnologyOf 43


Context Awareness“Context is any evidence that can be used to

support arguments for the conditions of the situation of any subject or target, which influences their interactive behavior”

• PerCom to be minimally intrusive, has to be context aware.

• User, system and environment context• Challenges:

– How does system obtain these information?– Where is context stored?– How frequently does context have to be consulted?



Trust• Enable systems to exchange information even

without the intervention of administrators to authorize these interactions

• How to grant users access to resources and information based on their trustworthiness rather than the application of conventional techniques that map authorizations to access rights.

• Challenges:– Unsavory uses (targeted spam, blackmail)

password-based protocols or biometric authentication?



Privacy• Huge amounts of information will be shared and

exchanged in pervasive computing environments

• With context-based services this question arise:

– Do you want this information shared?– How can you trust the technology?– What does the environment itself do?– How can you secure the access to private information?



Security• Security mechanisms for pervasive environments

must be– scalable to the small resource– able to deal with devices and environments of unknown

origin– adaptive to the dynamics of mobile computing



Context, Trust, Privacy and Security



introduction to pervasive computing

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