What is Ubiquitous Computing? Ubiquitous computing (alias: Pervasive Computing) is a paradigm in which the processing of information is linked with each activity or object as encountered. It involves connecting electronic devices, including embedding microprocessors to communicate information. Devices that use ubiquitous computing have constant availability and are completely connected. Ubiquitous computing focuses on learning by removing the complexity of computing and increases efficiency while using computing for different daily activities. Ubiquitous computing is also known as pervasive computing, everyware and ambient intelligence.

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ABSTRACT
Ubiquitous computing refers to embedding computers and communication in our environment.
Ubiquitous computing provides an attractive vision for the future of computing. The idea behind the
ubiquitous computing is to make the computing power disappear in the environment, but will always be
there whenever needed or in other words it means availability and invisibility. These invisible computers
won’t have keyboards or screens, but will watch us, listen to us and interact with us. Ubiquitous
computing makes the computer operate in the messy and unstructured world of real people and real
objects. Distributed devices in this environment must have the ability to dynamically discover and
integrate other devices. The prime goal of this technology is to make human life more simple, safe and
efficient by using the ambient intelligence of computers.

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2.0 INTRODUCTION
2.1 Evolution of Ubiquitous Computing
Ubiquitous Computing defines a major evolutionary step in work that began in the mid-1970s, when the
PC first brought computers closer to people. In Weiser’s vision, however, the idea of making a computer
personal is technologically misplaced. In fact, it keeps computing separate from our daily life. Although
the PC has not delivered the full potential of information technology to users, it certainly took a first step
toward making computers (if not computing) popular (if not pervasive). It was also an instrumental
factor in the phenomenal growth of hardware components and the development of graphical user
interfaces.
Figure : System view of pervasive computing. The mobile computing goal of “anytime anywhere”
connectivity is extended to “all the time everywhere” by integrating pervasiveness support technologies
such as interoperability, scalability, smartness, and invisibility.
Ubiquitous computing environments involve the interaction, coordination, and cooperation of numerous,
casually accessible, and often invisible computing devices. These devices will connect via wired and
wireless links to one another as well as to the global networking infrastructure to provide more relevant
information and integrated services. Existing approaches to building distributed applications, including
client/server computing, are ill suited to meet this challenge. They are targeted at smaller and less
dynamic computing environments and lack sufficient facilities to manage changes in the network
configurations. Networked computing devices will proliferate in the user’s landscape, being embedded
in objects ranging from home appliances to clothing. Applications will have greater awareness of

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context, and thus will be able to provide more intelligent services that reduce the burden on users to
direct and interact with applications. Many applications will resemble agents that carry out tasks on
behalf of users by exploiting the rich sets of services available within computing environments.
Ubiquitous Computing is also known by its alternative “Pervasive Computing” and basically user over
“Ubiquitous”. So, hereafter the report will show Pervasive rather Ubiquitous.
Pervasive Computing is a technology that pervades the users’ environment by making use of multiple
independent information devices (both fixed and mobile, homogeneous or heterogeneous)
interconnected seamlessly through wireless or wired computer communication networks which are
aimed to provide a class of computing / sensory / communication services to a class of users, preferably
transparently and can provide personalized services while ensuring a fair degree of privacy / non-
intrusiveness.
Pervasive computing can be explained in two different perspectives:
1. User view
2. Technological view
User view
For an end user Pervasive approach act as a method of augmenting human abilities in context of tasks. It
provides Interaction transparency which means that the human user is not aware that there is a computer
embedded in the tool or device that he or she is using.
Technological view
It means access to information and software applications are available everywhere and anywhere.
Technically pervasive computing involves in embedding intelligence and computing power to devices
which are part of our daily life. As the word ‘Pervasive’ means, we create an environment with
intelligence and which can communicate with each other. This technology is intended for mobile as well
as localized devices. It must also possess the ability to locate an object or a user using provisions such as
Global Positioning System (GPS). After positioning, a dynamic link must be setup for communication
which may use the recent concept of ADHOC networking. User can interact with and control these
devices using steerable interfaces, using voice and gesture recognition facilities.

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It may also be seen as the as the technology that is a combination of Personal computing, Distributed
Computing Technology and one or more of the following:
1. Internetworking technology
2. Invisible computing technology
3. Wearable computing technology
4. Mobile Computing Technology
2.2 Distributed computing
With the advent of networking, personal computing evolved to distribute computing. As
computers became connected, they began to share capabilities over the network. Distributed computing
marked the next step toward Pervasive Computing by introducing seamless access to remote information
resources and communication with fault tolerance, high availability, and security. Although the World
Wide Web was not designed to be a distributed computing infrastructure, its networking ubiquity has
made it an attractive choice for experimenting with distributed computing concepts. It has also created a
culture that is substantially more amenable to the deployment of Pervasive Computing environments
than the culture that existed when Weiser first articulated his vision. The ad hoc nature of the Web’s
growth has proved that we can distribute computing capabilities in a big way without losing scalability.
The simple mechanisms for linking resources have provided a means for integrating distributed
information bases into a single structure.
Most importantly, the Web has pioneered the creation of a nearly ubiquitous information and
communications infrastructure. Many users now routinely refer to their point of presence within the
digital world—typically, their homepages, portals, or e-mail addresses. The computer they use to access
these “places” has become largely irrelevant. Although the Web does not pervade the real world of
physical entities, it is nevertheless a potential starting point for Pervasive Computing.
2.3 Mobile computing
Mobile computing emerged from the integration of cellular technology with the Web.4 Both the
size and price of mobile devices are falling every day and could eventually support Weiser’s vision of
pervasive inch-scale computing devices readily available to users in any human environment. Cellular

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phone systems that separate the handset from the subscriber identity module (SIM) card approximate
this model of operation. Subscribers can insert their SIM card and automatically use any handset,
placing and receiving calls as if it were their own phone. Users can already access the same point in the
Web from several different devices—office or home PC, cell phone, personal digital assistant, and so
forth. In this sense, for most users, what matters is the view a particular machine provides of the digital
world. SIM cards also demonstrate that the end system is becoming less important than the access to the
digital world. In this sense, we are well on
The way to computers “disappearing,” freeing users to focus beyond them. The “anytime anywhere”
goal of mobile computing is essentially a reactive approach to information access, but it prepares the
way for Pervasive Computing proactive “all the time everywhere” goal. As Figure 1 shows, pervasive
computing is a superset of mobile computing. In addition to mobility, pervasive systems require support
for interoperability,
Scalability, smartness, and invisibility to ensure that users have seamless access to computing whenever
they need it.
Mobile computing and communication is one of the major parts of the pervasive computing system.
Here data and computing resources are shared among the various devices. The coordination between
these devices is maintained through communication, which may be wired or wireless. With the advent of
Bluetooth and Ad hoc networking technologies the wireless communication has overtaken the wired
counterpart.
The reduction in size and cost of processor chips made it possible to implement it in every field of life.
Nowadays about 99% of processors made are for embedded devices compared to the PC applications.
Voice and Gesture recognition along with steerable interface will make the interactions and use of this
management can enhance the performance of such systems devices more user friendly. Efficient security
and privacy policies along with power

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3.0 Pervasive Computing Model:
3.1 Necessary technological advances
The technological advances necessary to build a Pervasive Computing environment fall into four broad
areas: devices, networking, middleware, and applications.
Figure 2.1 Pervasive computing framework. Middleware mediates interactions with the networking kernel on the user’s
behalf and keeps users immersed in the pervasive computing space.
3.2 Elements of Pervasive Computing Systems
Components of Infrastructure for Pervasive Computing include Mobile computing devices, Fixed
computing devices, Multimode RF Mobile communication infrastructure <Fixed-to-Mobile and Mobile-
to-Fixed communication system interfaces>, Trust system (security and privacy), Protocol stacks and
Personalized service frameworks.
3.3 What should the Infrastructure provide?
1. Pervasive Computing Infrastructure has to comprise of computing elements, communicating
elements, sensors, actuators, and interface devices.
2. Computation to be available widely and freely (not free of cost).
3. Intermittent connectivity has to be a supported feature due to physical limitations pertaining to
power, cost, bandwidth and network congestion.
4. Bluetooth and other choices address small-distance networking issues and allow intermittent
connection.

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5. The infrastructure has to offer seamless connectivity to the devices / entities / services.
6. It has to support placement and location of uniquely identifiable “information tags / trackable
tags” to all devices / entities in the Pervasive Computing environment.
7. User’s environment must be able to be aware of the user’s context.
Roaming Environment: An environment that allows connectivity and communication to the services
outside the home zone is called a Roaming Environment. Some sample devices that may involve
Roaming-based access <fixed / mobile roaming>:
1. PDAs / Palmtops / Pocket PCs / Cell phones / Smart phones / WAP phones
2. Laptops / Tablet PCs / Notebook PCs
3. Desktop PCs / Servers / Web TVs
4. Kiosks
5. Invisible computing devices / Smart interactive posters
6. Wearable computers
3.4 Pervasive Computing Devices
An intelligent environment is likely to contain many different device types:
1. Traditional input devices, such as mice or keyboards, and output devices, such as speakers or
light-emitting diodes;
2. Wireless mobile devices, such as pagers, personal digital assistants, cell phones, palmtops, and
so on; and
3. Smart devices, such as intelligent appliances, floor tiles with embedded sensors, and biosensors.
Ideally, Pervasive Computing should encompass every device worldwide that has built-in active
and passive intelligence. The University of Karlsruhe’s MediaCup project is an experimental
deployment of everyday objects activated in this sense. The project’s guiding principle is to augment
objects with a digital presence while preserving their original appearance, purpose, and use.
Sensors that automatically gather information, transfer it, and take actions based on it represent an
important subset of pervasive devices. For example, sensors based on the Global Positioning System

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provide location data that a device can translate into an internal representation of latitude, longitude, and
elevation. Stereo camera vision is another effective sensor for tracking location and identity in a
pervasive environment. These fast-processing, two-lens digital cameras can record both background
images and background shapes. The results are much more robust for tracking motion such as gestures.
3.5 Basic Aspects :
Device Technology for Pervasive Computing include Power-provisioning technologies, Display
technologies, Memory technologies, Communication technologies, Processor technologies, Interfacing
technologies, Sensor Technologies and Authentication Technologies.
3.6 Technology Aspects :
• Low-power Device Technologies
Since many of the devices involved in the pervasive computing environment may have to be small in
size and may have to live on their battery / power units, consumption of lower power, extension of
power provisioning period etc. assume critical significance. In addition, prevention from excessive
heating also requires attention. Power requirements can be reduced by several means right from material
selection and chip-level designing to software designing and communication system designing. Power
provisioning technology including the Battery design technology plays a very important role in the
process.
• Batteries as Power Provisioning Devices
1. Key issue: Size and weight of the batteries versus the power capacity and price
2. Bottleneck: Relatively slower advances in the battery technology compared to those in other
fields like display and storage technologies
3. Major choices available: Nickel-Cadmium (NiCd: 12-27 hrs. standby time), Nickel-Metal-
Hydride (NiMH: 16-37 hrs. standby time), Lithium-Ion (Li-ion: 21-50 hrs. standby time),
Lithium-Polymer Cell based batteries (> 60 hrs. standby time, flexible shapes) etc.

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3.7 Display Device Technologies
Not all pervasive computing devices need display elements but those needing them may
have a range of different requirements in terms of:
• Display-size
• Display-shape
• Display-resolution
• Display-color richness
• Display viewing angles to be supported
• Display power provisioning constraints
• Display refresh rates etc.
3.8 Major Display Device Technologies
• Cathode Ray Tube based Displays (CRTs)
• Liquid Crystal Displays (LCDs)
• Active Matrix Displays
• Thin Film Transistor Displays (TFTs)
• Passive Matrix displays
• Single Scan Displays (Colour Super-Twist Nematic: CSTNs)
• Dual Scan Displays (Dual Super-Twist Nematic: DSTN)
• High-Performance Addressing displays (HPAs)
• Light Emitting Diode based Displays (LEDs)
• Organic LED based Displays (OLEDs)
• Light-Emitting Polymer based Displays (LEPs)
• Chip-on-Glass Displays (CoGs)
• Liquid Crystal on Glass Displays (LCoGs)

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3.9 Pervasive middleware :
Like distributed computing and mobile computing, Pervasive Computing requires a middleware “shell”
to interface between the networking kernel and the end-user applications running on pervasive devices.
As Figure 2 shows, this pervasive middleware
will mediate interactions with the networking kernel on the user’s behalf and will keep users immersed
in the Pervasive Computing space. The middleware will consist mostly of firmware and software
bundles executing in either client-server or peer-to-peer mode.
User interfaces are another aspect of middleware. Standard Web browsers represent the high end
of interface sophistication. They use more color, graphics, and controls than users typically expect on
pervasive devices. Mobile computing has already introduced micro browsers. For example, phone.com’s
UP Browser is implemented on several commercially available digital phones. “Middleware must mask
heterogeneity to make pervasive computing invisible to users.”
3.10.Pervasive applications :
Pervasive Computing is more environment-centric than either Web-based or mobile computing. This
means that applications will guide the middleware and networking issues to a large extent. Consider a
heart patient wearing an implanted monitor that communicates wirelessly with computers trained to
detect and report abnormalities. The monitor should know when to raise the alarm, based on its
knowledge about the environment. So this is much more than simple wireless communication.
EliteCare (www.elite-care.com) is an assisted living complex that applies similar technologies to
improve the quality of life for elderly residents.
3.11 Current Embedded Technology :
Embedded technology is the process of introducing computing power to various appliances. These
devices are intended to perform certain specific jobs and processors giving the computing power are
designed in an application oriented way. Computers are hidden in numerous information appliances
which we use in our day-to-day life. These devices find there application in every segment of life such
as consumer electronics, avionics, biomedical engineering, manufacturing, process control, industrial,
communication, defense etc…

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Embedded systems, based on there functionality and performance requirement are basically categorized
as:
1. Stand alone systems
2. Real time systems
3. Networked systems
4. Mobile devices
Stand alone systems work in standalone mode, taking inputs and producing desired outputs. They do not
have any dependence on other systems. Embedded systems in which some specific work has to be done
in a specific time period are called Real time systems. Meeting the dead line is the most important
requirement of a real time system. In Hard real time systems, missing a deadline may lead to a
catastrophe and in Soft real time systems such problem is not present. Systems which are provided with
network interfaces and accessed by networks such as LAN or the Internet are called Networked
Systems. Networking may be wired or wireless. Mobile devices are devices which move from one
location to another, like mobile phones, PDA’S etc.
Today, many people carry numerous portable devices, such as laptops, mobile phones, PDAs and mp3
players, for use in their professional and private lives. For the most part, these devices are used
separately i.e, their applications do not interact. However, if they could interact directly, participants at a
meeting could share documents or presentations, business cards would automatically find their way into
the address register on a laptop and the number register on a mobile phone, as commuters exit a train,
their laptops could remain online; likewise, incoming email could now be diverted to their PDAs.
In such a distributed environment where several embedded devices has to and co-ordinate with each
other. For this a communication link is required which may be wired or wireless. In initial stages of
Networked embedded system environments wired connection was preferred as it provided a safer and
faster channel for communication. But the cost, immovability and the cables running around the
floorboards became less attractive. On top of this, dishing out the cash for network cards, cables and a
hub/switch reserved this practice to the more elite computer users, until wireless networking hit the
scene.
Infrared communication was initially used for wireless communication because of the low cost offered
by it. But it suffered from the limitation that it can be used only within Line Of Sight. IEEE introduced
802.11 as the international standard for wireless LANs. This used a 2.4GHz transmission band while

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maintaining a steady 1-2 Mbps bandwidth rate. Being that this was extremely slow compared to
100Mbit wired LANs, it took a while for the 802.11 standard to develop into a viable solution, achieved
shortly after with the 802.11a, b and g standards, offering bandwidth ranging from 11Mbps to 54Mbps.
Although this is still considerably short of the 100Mbit found in cabled networks, 802.1 x wireless
technologies is now literally regarded as the future of networking. Bluetooth, Wi-Fi, Wi-Max are the
latest solutions, under the 802.1x standard, for wireless communication over short, medium and long
range communication respectively.
4.0 Issues and Challenges:
4.1 Pervasive Computing System Design Approaches
Recollect that Four Principles of Pervasive Computing are:
• Distributedness / Decentralization
• Diversification / Specialized services
• Connectivity (regular or intermittent)
• Simplicity Possible solution approaches
• Top-down approach
• Bottom-up approach
• Hybrid approach
• Ad-hoc / one -off approach
•
Principal issues related to design of Pervasive Computing Systems include:
• Feature -specific issues
• Form-factor-(size)-specific issues
• Power-provisioning issues
• Weight-specific issues
• Shape-specific issues
• Cooling-specific issues
• Connectivity-specific issues
• User Interface -specific issues
• Body-safety-specific issues <not for all devices>
• Security-specific issues
• Processor-choice-specific issues
• Operating System-specific issues
• Development and execution-environment-specific issues
• Cost-specific issues
• Regulatory issues

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Criteria for acceptable pervasive computing design solutions include characteristics like
the
• Privacy & Security
• Effectiveness of Approach Across Networks
• Economic considerations
• Quality considerations
• Monitoring mechanisms
• Adaptability and Flexibility
• Practicability
• Sustainability
As a superset of mobile computing, Pervasive Computing subsumes mobile computing’s research issues
while opening up new ones unique to itself. In all cases, pervasive applications should disappear into the
environment.
4.2 Issues and challenges in Pervasive Computing :
4.2.1 Scalability
Future Pervasive Computing environments will likely face a proliferation of users, applications,
networked devices, and their interactions on a scale never experienced before. As environmental
smartness grows, so will the number of devices connected to the environment and the intensity of human
machine interactions.
Traditional development requires recreating the application for each new device. Even if an enterprise
could generate new applications as fast as it adds new devices, writing application logic only once—
independent of devices—would have tremendous value in solving the applications scalability problem.
Furthermore, applications typically are distributed and installed separately for each device class and
processor family. As the number of devices grows, explicitly distributing and installing applications for
each class and family will become unmanageable, especially across a wide geographic area.
4.2.2 Heterogeneity
Conversion from one domain to another is integral to computing and communication. Assuming that
uniform and compatible implementations of smart environments are not achievable, Pervasive
Computing must find ways to mask this heterogeneity—or uneven conditioning, as it has been called—
from users. For instance, a sophisticated laboratory and a department store may always differ in their

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infrastructural smartness. Pervasive Computing must fill this gap at some level, say middleware, to
smooth out “smartness jitter” in the user’s experience.
For networking, developers have faced protocol mismatch problems and learned how to tackle the large
dynamic range of architectural incompatibilities to ensure trans network interoperability. Mobile
computing has already achieved disconnected operation, thereby hiding the absence of wireless
coverage from the user. Middleware may borrow similar concepts to dynamically compensate for less
smart or dumb environments so that the change is transparent to users.
But the real difficulty lies at the application front. Today, applications are typically developed for
specific device classes or system platforms, leading to separate versions of the same application for
handhelds, desktops, and cluster-based servers. As heterogeneity increases, developing applications that
run across all platforms will become exceedingly difficult.
4.2.3 Integration
Though Pervasive Computing components are already deployed in many environments, integrating them
into a single platform is still a research problem. The problem is similar to what researchers in
distributed computing face, but the scale is bigger. As the number of devices and applications increases,
integration becomes more complex. For example, servers must handle thousands of concurrent client
connections, and the influx of pervasive devices would quickly approach the host’s capacities. We need
a confederation of autonomous servers cooperating to provide user services.
Integrating Pervasive Computing components has severe reliability, quality of service, invisibility, and
security implications for pervasive networking. The need for useful coordination between confederation
components is obvious. This coordination might range from traditional areas such as message routing or
arbitrating screen usage to new challenges such as deciding which application can use a room’s light
intensity to communicate with the user.
4.2.4 Perception: Context awareness :
Most computing systems and devices today cannot sense their environments and therefore cannot make
timely, context-sensitive decisions Pervasive Computing, however, requires systems and devices that

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perceive context. Mobile computing addresses location- and mobility-management issues but in a
reactive context—responding to discrete events.
Pervasive Computing is more complex because it is proactive. Intelligent environments are a
prerequisite to Pervasive Computing.
Perception, or context-awareness, is an intrinsic characteristic of intelligent environments. Implementing
perception introduces significant complications: location monitoring, uncertainty modeling, real-time
information processing, and merging data from multiple and possibly disagreeing sensors. The
information that defines context awareness must be accurate; otherwise, it can confuse or intrude on the
user experience.
ComMotion, a location-aware computing environment that addresses these issues for mobile users, is
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.
4.2.5 Smartness: Context management :
Once a Pervasive Computing system can perceive the current context, it must have the means of using
its perceptions effectively. Richer interactions with users will require a deeper understanding of the
physical space.
Smartness involves accurate sensing (input) followed by intelligent control or action (output) between
two worlds, namely, machine and human. For example, a Pervasive Computing system that
automatically adjusts heating, cooling, and lighting levels in a room depending 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. Pervasive Computing requires systems and devices that
perceive context.
4.3 Distributed Computing Environment:
The essence of that vision was the creation of environment saturated with computing and
communication capability, yet gracefully integrated with human users. The field of distributed systems

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arose by the intersection of personal computer and Local Area Network. With the appearance of wireless
LANs embedded systems for mobile clients was introduced. These two laid the foundation for the
concept of Pervasive computing.
4.3.1 Ambient Intelligence
Objects in pervasive environment are considered to have Ambient Intelligence. Ambient Intelligence
refers to a vision of the future, in which people are empowered by an electronic environment that is
aware of their presence, and is sensitive and responsive to their needs. It aims at improving the quality of
life by creating the desired atmosphere and functionality via intelligent, personalized interconnected
systems and services. The transition to such a world requires a paradigm shift in user-system interaction.
Speech and gesture recognition modalities address user benefits such as freedom of movement, and are
natural candidates for such interactions.
However, implementing these modalities in e.g. a home environment is radically different from
implementing known methods such as buttons, dials and remote controls. Smart objects may play an
important role in bridging this gap. People have a life-time experience in manipulating tangible objects,
and can perform these manipulation tasks with a minimal amount of attention.
Ambient Intelligence refers to electronic environment that are sensitive and responsive to the presence
of people. It builds on advanced networking technologies, which allow robust, ad-hoc networks to be
formed by a broad range of mobile devices and other objects. By adding adaptive user-system
interaction methods, based on new

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insights in the way people like to interact with computing devices, digital environments can be created
which improve the quality of life of people by acting on their behalf.
Key characteristics of such environments are: ubiquity, awareness, intelligence, and natural interaction.
Ubiquity refers to a situation in which we are surrounded by a multitude of interconnected embedded
systems, which are invisible and moved into the background of our environment. Awareness refers to
the ability of the system to locate and recognize objects and people. Intelligence refers to the fact that
the digital surrounding is able to analyze the context, to adapt itself to the people that live in it, to
learn from their behavior, and eventually to recognize as well as show emotion. Natural Interaction
finally refers to advanced modalities like speech-, gesture- and object recognition, which will allow a
more natural communication with the digital environment than is possible today.

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Evolutionary development of Pervasive computing environment and Relation between Pervasive
computing with Distributed systems and mobile computing.
We envisage that in the near future, mobile and embedded devices will be capable of providing
customized information, services and computation platforms. People will need the cooperation of
services available in their resource rich vicinity to satisfy their information needs. Service composition
systems for the pervasive computing environment need a different design approach than those developed
for wired services. Service composition architectures in wired infrastructure assume the existence of a
centralized composition entity that carries out the discovery, integration and execution of services
distributed over the web or network. This Client/Server based computing, are ill suited to meet this
challenge. They are targeted at smaller and less dynamic computing environments and lack sufficient
facilities to manage changes in the network configurations.
4.3.2 Mobile Ad hoc Networking
So we introduce a system architecture which provides an integrated and comprehensive framework for
building pervasive applications. It includes a set of services that help to structure applications and
simplify the task of coping with constant change. So a pervasive computing environment is expected to
be based on the recent progresses and advances in computing and communication technologies.
Next generation of mobile communications is likely to be based on an infrastructure less Mobile Ad hoc
Networks (MANETs).

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A MANET is a collection of wireless nodes that can dynamically form a network to exchange
information without using any pre-existing fixed network infrastructure. Ad-hoc mode essentially
eliminates the need for an access point. An Ad-Hoc network only requires wireless adapters to
communicate hence significantly reducing the cost and maintenance compared to a network structured
around an access point. Most or all nodes in the network participate in the network tasks. While
traditional networks are static, i.e., nodes do not move and new nodes are not attached to or detached
from the network on a frequent basis, the ad-hoc network is extremely dynamic. The nodes are
autonomous and may have varying mobility, and they may enter and leave the network for some reason
or another, for example, a mobile node may move out of reach of other nodes, thus being unable to send
or receive , or a node may suffer from power failure or destruction and often act as routers at the same
time. Another important difference between traditional and ad hoc networks is that traditional networks
tend to be wired, where as an ad hoc network most likely is wireless, which increases their complexity
even further.
4.4 Communication :
4.4.1 Bluetooth :
Blue tooth is an economical communication technology that allows communicating with one another
wirelessly within a 30 feet or 10 meter radius. Blue tooth is specially designed for short range
communication. An important outcome of this design is the low power consumption which in turn
makes these devices portable. Bluetooth wireless technology makes use of radio frequency technology
to communicate through the air. RF incorporates high power transmitters and receivers tuned to a
particular frequency range for long ranges as in TV. Short range requires less power and thereby
batteries can suffice the power requirements. RF can penetrate the obstacles and there is no requirement
of line sight communication. Bluetooth technology operates in 2.4 GHz spectrum. It has a data
transmission rate of 700 Kbps. Bluetooth link between two devices consists of of a master and a slave. A
piconet consists of a single master and all slaves in close proximity. Only one master is allowed in a
single piconet. The ability to form piconets is a significant advantage for pervasive computing
environment design. We can use TCP/IP protocol on top of Bluetooth technology. Bluetooth has
protocols for “inquiry” and “connection” between devices. First Bluetooth piconets are formed and then

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using TCP/IP protocol is used for establishing communication between the devices in an environment.
Various other wireless standards which can be used in mobile, distributed systems are,
• Wireless LAN IEEE 802.11b (Wi-Fi), having a range of about 200 m. It uses a radio frequency of
2.4 GHz band with data transmission rate of 11 Mbps. GSM phone with transmission rate of 9.6 Kbps.
• UMTS – 3G mobile 114 kbps (vehicle), 384 Kbps (pedestrian) 2 Mbps(stationary)
• HIPERLAN & IEEE 802.11a using RF of 5 GHz band with data rate currently 20 Mbps eventually
54 Mbps
• Home RF derived from DECT 10Mbps
• Infrared transmission gives a rate of 4Mbps, but can be used only for line of sight communication (so
not preferred).
4.4.2 Context Awareness :
Context awareness translates to adaptation of the behavior of an application as a function of its current
environment. This environment can be characterized as a physical location, an orientation or a user
profile. A context-aware application can sense the environment and interpret the events that occur within
it. In a mobile and wireless computing environment, changes of location and orientation are frequent.
Invisibility of applications will be accomplished in part by reducing input from users and replacing it
with knowledge of context.
Context aware software components will exploit information such as the activities in which the user is
engaged, proximity to other devices and services, location, time of day and weather conditions.
Knowledge of context will also be required to enable adaptation to changing environmental conditions,
such as changing bandwidth and input and output devices, which can be brought about by mobility. The
infrastructure for pervasive computing should support context awareness by facilitating the gathering of
information from sources such as sensors and resource monitors; performing interpretation of data,
carrying out dissemination of contextual information to interested parties in a scalable and timely
fashion. Location identification of user is needed for a better understanding of context. For this Global
Positioning Systems (GPS) are employed.

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A very challenging aspect is interpretation, which involves steps such as integration of data from
different sources, inference, prediction based on context history, resolution of inconsistencies between
context data from different sources, and provision of estimates of the accuracy of contextual
information. Capture and storage of past experiences can be used to solve new problems in the future.
Experiences are made of events and computers have the ability to record them automatically. Human
users only have to recall that information from the computer when it is needed.
4.4.3 Adaption :
Adaptation is required in order to overcome the intrinsically dynamic nature of pervasive computing.
Mobility of users, devices and software components can occur, leading to changes in the physical and
virtual environments of these entities. Moreover, applications can be highly dynamic, with users
requiring support for novel tasks and demanding the ability to change requirements on the fly. It should
be the role of the infrastructure for pervasive computing to facilitate adaptation, which may involve
adapting individual software components and/or reconfiguring bindings of components by adding,
removing or substituting components. Adaptation may be done in an application-aware or application-
transparent manner. Dynamic adaptation can involve complex issues such as managing the adaptation of
software components that are used simultaneously by applications with different requirements, and
maintaining a consistent external view of a component that has behavior that evolves over time.
4.4.4 Steerable Interfaces :
They are a new class of interactive interfaces that can be moved around to appear on ordinary objects
and surfaces anywhere in a space. By dynamically adapting the form, function, and location of an
interface to suit the context of the user, such steerable interfaces have the potential to offer radically new
and powerful styles of interaction in intelligent pervasive computing spaces. We propose defining
characteristics of steerable interfaces and present the first steerable interface system that combines
projection, gesture recognition, user tracking, environment modeling and geometric reasoning
components within a system architecture. An essential element to realize this notion of “computing
woven into space” is a ubiquitous interface to computing access to pervasive computing resources
should be available everywhere. For instance, access to computing services has been through computer
monitors, touch screen panels, keyboards, mice, PDAs, cellular phones etc, all special surfaces and
devices available in the environment or carried by people.

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In this paper, we pursue an alternate vision for the pervasive computing interface, especially in the
context of intelligent environments. We propose that as computing disappears into the physical
environment, what matters most to the user is the interface to computing. The interface should appear
whenever the user needs it, wherever the user needs it, and in a form most suitable for natural
interaction. In particular, both input and output interfaces should be available to the user anywhere in
space, without the need for special devices.
To realize this, we introduce the concept of a steerable interface to computing that can be moved around
a physical environment on to ordinary objects or surfaces. Steerable interfaces are important as they
provide interaction wherever it is needed in a space. In many cases, the interface just appears when
needed and where needed, as a natural extension to the physical environment, without the user having to
perform any deliberate actions. And as the user neither carries nor approaches any special devices,
the interaction is casual. The user can also request for the interface anywhere through natural actions
such as simply asking or making a specific gesture. Steerable interfaces have the potential to change
how we access information in a number of different domains and applications.
For example, during shopping, information about a product can be made available right at the product
location when a shopper is in the vicinity of the product. At home, a television or a computer can appear
on demand on any wall or table or countertop. Steerable interfaces can also result in new forms of
entertainment such as games in the real world with virtual characters and hybrid theater combining the
real and the virtual.

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5.0 Emerging Pervasive Technologies:
5.1 Peer-to-Peer (P2P) networking
Napster popularized the application of P2P (peer-to-peer networking) products and now the same
technology has begun to sing a business melody. The basic idea behind it being the sharing of files and
programs and communicating directly with people over the Internet, without having to rely on a
centralized server. What it does is to create private workspaces for sharing files, exchanging
information, creating databases and communication instantly. Companies can now participate in B2B
marketplaces, cut out intermediaries and instead collaborate directly with suppliers. Peers on desktop
PCs can share files directly over a network. Renting computing power can solve resource problems in
smaller companies, thus improving the power of web applications.
5.2 Nano technology
We've seen science fiction flicks where miniature machines get into the human body and track cell
patterns and behavior like those of cancer cells and exterminate them. Molecule sized computers can be
manufactured to create new materials that can replace steel in all its properties and even withstand
temperatures of 6,500 degree Fahrenheit. It is predicted that these materials will soon be used to build
automobiles and office buildings. 'A la' - an invisible infrastructure!
5.3 Chips and the Net
Net-ready chips are a low cost method of getting on to the Internet. They follow all the necessary
Internet Protocols and can be embedded in home appliances that can then be easily connected to the
Internet. They function as tags that possess comprehensive information about the object that it is tagged
on to and include details like the date and place it was manufactured.
5.4 Wireless technology
Wireless Internet connection helps access the Net through cellular phones, Personal Digital Assistants
(PDAs) and Wireless laptops and this technology proposes enormous business opportunities. The sales

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force can avail real-time access to inventory records; price lists, order and customer account status and
can book a sale almost instantaneously. Constant communication with wireless gadgets (that cost many
degrees lesser than a laptop) can ensure that there is a constant feedback loop thus ensuring a new way
of reaching customers.
5.5 Voice computing: Tell your computer to switch on!
Voice recognition software will soon allow users to switch on their computers by just talking to them.
Even documents can be edited through voice commands. We'll finally be reaching out to the frontier
where man will be able to talk to all his machines and command them to do as he wishes.
5.6 IBM's pervasive computing lab
This is a futuristic playground where IBM tests and shows off technology that connects devices in a
seamless computing environment. The entire lab and all its rooms are a prime example of a web site.
The digital images on display in the picture frames on the living room wall can be controlled remotely.
Intelligent countertops in the kitchen recognize bar code labeled stuff and react accordingly.
5.7 E-web
Embedded devices in cars, refrigerators, shop floors, hospital rooms extend the Internet's role beyond
content providers and shopping assistants to companion and advisors. The Next-Gen web will be more
interactive with a swarm of specialized devices like sensors, and other appliances, all with Internet
access and the ability to communicate.
Basically easier computing that's available everywhere as needed, devices that are going to be easy to
use, as simple as calculators and telephones or ATMs. With an extensive range like mobile commerce to
home automation, and from the well-connected car to the convenience of small devices, Pervasive
Computing exemplifies a vision beyond the PC. Agreed that some of the technologies behind these
devices are in their infancy or evolutionary stages, so it may just be a question of time before all that is
promised is achieved.
6.0 HAVi-An Implementation in Consumer Appliance Environment :

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HAVi is a standard for home appliances consisting of a set of APIs, services, and a standard for
communication. HAVi’s primary goal is providing a dynamic service environment in which software
components can discover and interact with other. It provides mechanisms for devices to discover, query
and control other appliances on the home network, and provides system services such as message and
event.
Eight major consumer electronics manufacturers have come up with an open standard enabling home
entertainment devices to communicate intelligently with each other. The HAVi(Home Audio Video
Interoperability) standard promises to bring true platform independent interoperability to consumer
devices using high bandwidth IEEE 1394 (FireWire) as the connecting medium. Major consumer
electronics, software, semiconductor and computer manufacturers, namely Grundig, Hitachi, Panasonic,
Philips, Sharp, Sony, Thomson and Toshiba along with now over 30 other participants, have formed a
non-profit organization called HAVi (Home Audio Video Interoperability) for promoting the
development of interoperable consumer products. The goal of HAVi organization is to provide a
standard open architecture for intelligent audio and video devices to interoperate with each other
regardless of manufacturer, operating system, CPU or programming language used for implementation.
The simplest example can be time synchronization between different devices. TV set might get the
correct time from the broadcast stream and the other devices can query the TV and set their own clocks
according to it. Setting the VCR to record a program is a familiar situation users usually have problems
with. With HAVi enabled devices this task can be made very easy. User can select the program he
wishes to record with the Electronic Program Guide (EPG) residing on a digital TV set (or set- top-box).
The TV then locates an available recorder (e.g., a VCR or a recording DVD device) and commands it to
record the program supplying it with the time, length and channel parameters taken from the EPG. Thus,
the user doesn’t need to program or touch the recording device in any way
7.0 Security In Pervasive Computing Environments :

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As Computing devices are numerous and ubiquitous, the traditional authentication including login
schemes do not work well with so many devices. Proposed Solution is to Use biometrics for
authentication and at the same time, ensure security of biometric templates in an open environment.
User Interaction is with speech, gestures and movements and the sensors and computing devices are
‘aware’ of the user and in the ideal case are also aware of his ‘intent’.
7.1 Security and Privacy
• Consequences of a pervasive network
• Devices are numerous, ubiquitous and share
• The network shares the context and preferences of the user
• Smart spaces are aware of the location and intent of the user
7.2 Security Concerns
• Only authorized individuals need to be given access
• Authentication should be minimally intrusive
• Devices should be trustworthy
7.3 Privacy issues
• User should be aware of when he is being observed
• The user context should be protected within the network
• Need to balance accessibility and security
• Should be scalable with multiple users operating in the network
7.4 Physical Biometrics
• Fingerprint
• Hand Geometry
• Iris patterns

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7.5 Behavioral Biometrics
• Handwriting
• Signature
• Speech
• Gait
7.6 Chemical/Biological Biometrics
• Perspiration
• Skin composition(spectroscopy)
8.0 Advantages of pervasive computing :
The advantages of Pervasive Computing can be summarized as dramatically increased automation
without much obtrusive or visible use of computer infrastructure. We increasingly rely on the electronic
creation, storage, and transmittal of personal, financial, and other confidential information, and demand
the highest security for all these transactions and require complete access to time-sensitive data,
regardless of physical location. We expect devices – personal digital assistants, mobile phones, office
PC and home entertainment systems -- to access that information and work together in one seamless,
integrated system.
Pervasive Computing gives us the tools to manage information quickly, efficiently, and effortlessly. It
will help people make effective use of computing tools without requiring the knowledge of complex
devices, by means of a new class of intelligent and portable appliances or "smart devices" embedded
with microprocessors that allow users to plug into intelligent networks and gain direct, simple, and

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secure access to both relevant information and services. It gives people convenient access to relevant
information stored on powerful networks, allowing them to easily take action anywhere, anytime.
Pervasive Computing simplifies life by combining open standards-based applications with everyday
activities. It removes the complexity of new technologies, enables us to be more efficient in our work
and leaves us more leisure time and thus Pervasive Computing is fast becoming a part of everyday life.
9.0 Uses of Pervasive Computing :
Pervasive computing has many potential applications, from health and home care to environmental
monitoring and intelligent transport.
9.1 Some Business Uses of Pervasive Computing :
a) Healthcare:
i) records, lab order entry and results reporting (MRIs on the patient's TV)
ii) prescription writing (mistakes, loss of paper copy, forgeries)
iii) medications (what if every pill had a UPC code on it?)
iv) billing and costs (why do I have to file my records?)
b) personnel scheduling
i) Mall interviewing with semi-connected TabletPCs
ii) Vending: improved routing, re supply, ordering; price changes pushed to machines
iii) Service Industry: "Cable guy will be at your home between 8am and noon." / GPS
iv) MicroPayments: with cell phone for vending, train tickets.
v) Micro/Nano devices Hitachi's Mu Chip 0.4mm square, 128 bit ROM, Interrogated at 2.45GHz, useful
for documents, currency, shopping, preventing "shrinkage"
vi) Military: Operation Anaconda

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9.2 Some Personal Uses of Pervasive Computing :
a) Personal Information: PDA with wireless connections to web, broker, child's school, appointments,
telephone numbers
b) Flight Schedules: Your phone rings. Its the computer at American Airlines. Your flight departure is
delayed by 20 minutes.
c) Networked coffee shop: Wi-Fi at StarBuck's and Schlosky's
d) Location: finding friends at the mall (or hiding from)
e) Home interaction: The networked coffee pot/an alarm clock sync'd with Outlook / Electricity Peak
Conservation/Thermostat/Hot Water Heater connected via wireless network (security issues)
f) Car: schedule oil change seamlessly w/ garage; maps; traffic; kid movies streamed to back seat ("Only if
its quiet back there")

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10.0 CONCLUSION
The trends in pervasive computing are increasing the diversity and heterogeneity of networks and their
constituent devices .Pervasive computing is expected to bring an explosion in the number of devices in
our local environments. This paper presents a vision of a future computing landscape characterized by
the ubiquity of computing devices, the autonomy, dynamicity and the heterogeneity of system
components. This paper also provides a discussion of the challenges associated with such a vision,
framed around our conceptual model of pervasive computing which encompasses devices, users,
architecture, networking and communication, user interfaces and security policy. With more progress in
the fields like MANET, Artificial Intelligence, Natural language processing capabilities and energy
management, the infrastructure limitation present currently is supposed to be broken, which will result in
revolutionary changes through the implementation of Pervasive computing technology.

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11.0 REFERENCE
1] M. Weiser, "The computer for the 21st century," Scientific American, vol. 272, pp. 78-89, 1995.
[2] S.Dritsas, D.Gritzalis, and C.Lambrinoudakis, "Protecting privacy and anonymity in pervasive
computing: trends and perspectives", Telematics and Informatics, vol. 23, pp. 196-210, 2006.
[3] International Journal of Multimedia and Ubiquitous Engineering Vol. 2, No. 1, January, 2007
4] Ubiquitous Computing Environment Threats and Defensive Measures Dr. Byeong-Ho KANG
International Journal of Multimedia and Ubiquitous Engineering Vol. 2, No. 1, January, 2007
[5] Towards a Discipline for Evaluating Ubiquitous Computing Applications J. Scholtz, S. Consolvo
IRS-TR-04-004 January 2004
[6] Keefe, D., & Zucker, A. (2003). Ubiquitous Computing Projects: A Brief History (Technical Report
No. P12269): SRI International.
[7]www.doc.ic.ac.uk/~mss/OV2001.pdf
[8]www.cs.princeton.edu/~chenhan/papers/percom2003.pdf
[9]www.wileydreamtech.com
[10]www.cs.hut.fi/Opinnot/Tik-86.174/pervasive.pdf