M.SARAVANA KARTHIKEYAN
PERVASIVE COMPUTING
Unit I
Part A
1. What is pervasive computing?
Pervasive Computing is a technology that pervades the users‟ environment by making use ofmultiple independent information devices (both fixed and mobile, homogeneous orheterogeneous) interconnected seamlessly through wireless or wired computer communicationnetworks which are aimed to provide a class of computing / sensory / communication services toa class of users, preferably transparently and can provide personalized services while ensuring afair degree of privacy / non-intrusiveness.
Pervasive computing integrates computation into the environment, rather than having computers which are distinct objects. Pervasive computing is the trend towards increasingly ubiquitousan information environment in which users have access to ICTsthroughout the environment. This trend is particularly associated with the growth ofwireless technologies that allow users to access online information and services remotelyand synchronize data between different computers.
2.State Moore’s law
Moore’s law states that, “For every 18 months, the number of transistors in an integrated electronic circuit gets doubled with increased performance and without any increase in size”.
3. What are the principles of pervasive computing?
Decentralization
Diversification
Connectivity
Simplicity
4. What are the basic aspects or of a Pervasive Computing environment?
Multiple devices like car key, mobile phones, car audio system, and navigation system
are integrated in the system.
A large number of different interfaces are used to build an optimized user interface.
There is a concurrent operation of offline, and temporary online systems.
A large number of specialized computer systems are interconnected via local buses and
the internet.
Short range and wide area wireless communication are integrated.
Security element provide unauthorized access.
5. List the characteristics of a Pervasive Computing?
Privacy & Security
Effectiveness of Approach Across Networks
Economic considerations
Quality considerations
Monitoring mechanisms
Adaptability and Flexibility
Practicability
Sustainability
6.List the characteristics of a pervasive computing environment
Minimal user distraction
Collaborative interaction
User mobility
Context awareness (user/time/location)
Resource and location discovery
Ambient information, calm technology
Event notification
Adaptive interfaces
Invisibility—everyday object augmentation
Anytime/anywhere
7. Define ubiquitous computing.
Mark D.Weiser defined ubiquitous computing as,“The most profound technologies are those that disappear. They weave themselves intothe fabric of everyday life until they are indistinguishable from it”.
This invisible computing is accomplished by means of "embodied virtuality," theprocess of drawing computers into the physical world which in turn made computing, omnipresent and appears everywhere all the time.
8. List the issues involved in pervasive computing technology?
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
9. What are the hardware Device Technology for Pervasive Computing?
Power-provisioning technologies
Display technologies
Memory technologies
Communication technologies
Processor technologies
Interfacing technologies
Sensor Technologies
Authentication Technologies
10. Define Low-power Device Technologies?
Technology that supports device performance with optimized resources in all aspects is said to be low power device technology. As many of the devices involved in the pervasive computing environment may have to besmall 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, preventionfrom excessive heating also requires attention. Power requirements can be reduced by severalmeans right from material selection and chip-level designing to software designing andcommunication system designing. Power provisioning technology including the Battery designtechnology plays a very important role in the process.
11. List the major display device technologies in pervasive computing?
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)
12. What are all the major hardware components considered while designing a pervasive device?
The pervasive computing devices are needed to be small, less power consuming, highly human interacted. So the following the components are targeted..
Battery (Nickel Cadmium,Nickel Metal Hydride,Lithium-ion)
Displays (CRT,LCD,LED,OLED,CoG,LCoG)
Memory (SRAM,DRAMUt-RAM,MRAM,FRAM)
Processors (Intel SpeedStep Technology,Crusoe processor)
13. What is the latest technology emerged in batteries?
The latest in battery technology is the emergence of lithium polymer cells, which use a gelmaterial for the electrolyte. The batteries are made from a few thin and flexible layers, and do
not require a leak-proof casing. This means the batteries can be made in any shape or size.
14. Define Crusoe processor.
The Crusoe processor consists mostly of software. The relatively small processor is designed as a128-bit very long instruction word processor capable of executing up to four operations percycle.
15. List the human machine interfaces associated with mobile and pervasive computing devices.
Navigation keys
Haptic interfaces
Keyboards
Handwriting recognition
Speech recognition
Touch screen technology
16. What do you mean by “Fitaly”?
The fitaly keyboard arranges the letters based on their individual frequency and the probability oftransitions in the English language. The name is derived from the orders of letters in one of thetop rows of the layout, just as the QWERTY layout.
17. What is an Octave?.
Another approach to enter a text without real or on-screen keyboard is used by octave from e-acute.Octave maps each letter of the alphabet to one of eight unique strokes. The strokes arebased on a common characteristics part of the letters they represent and are located around thetips of a star shaped pattern.
18. What is meant by Bio-Metrics?
Biometrics is the science and technology of measuring and analyzing biological data. Ininformation technology, biometrics refers to technologies that measure and analyze human bodycharacteristics, such as DNA, fingerprints, eye retinas and irises, voice patterns, facial patterns
and hand measurements, for authentication purposes.
19. List the operating systems available for mobile computing devices like PDA, other embedded systems.
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M.SARAVANA KARTHIKEYAN
Palm OS
EPOC OS
WINDOWS CE OS
QNX NEUTRINO
BeOS
EMBEDDEDLINUX
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M.SARAVANA KARTHIKEYAN
20. What is PALM OS?
Palm OS is the computer operating system that provides a software platform for the Palm seriesof handheld personal digital assistants (PDAs) made by Palm Inc. According to Palm, Palm OSwas designed from the beginning to fit into a palm-size device of a specific size and with aspecific display size.
21. Explain briefly about BE OS.
BeOS is a powerful OS designed primarily for Multimedia desktop use. Originally BeOS wasdesigned for a custom computer system known as the BeBox that had special multimedia
input/output features, and was later ported to the Macintosh, and finally ported to the PC.
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M.SARAVANA KARTHIKEYAN
22. What are all the device characteristics which require J2me?
Small amount of available memory (128-512kb)
Limited energy (battery operated)
Connected to a network
Restricted graphical display capabilities
23. List the configuration and technologies available for pervasive devices based on J2me?
Connected device configuration
Connected , Limited device configuration
Embedded Java
Java card
Real time java
24. Define Roaming Environment?
Roaming Environment: An environment that allows connectivity and communication to the services outside the home zone is called a RoamingEnvironment. Some sample devices that mayinvolve Roaming-basedaccess <fixed / mobile roaming>:
PDAs / Palmtops / Pocket PCs / Cell phones / Smart phones / WAP phones
Laptops / Tablet PCs / Notebook PCs
Desktop PCs / Servers / Web TVs
Kiosks
Invisible computing devices / Smart interactive posters
Wearable computers
25. What are the components of pervasive computing?
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.
26. How does mobile internet protocol overcome the address problems of IPv4?
To overcome the address problems of IPv4 for mobile nodes mobile IP uses two IP addresses: afixed home address and care of address that changes at each new point of attachment.
27. What are three steps involved in the process of Synchronization?
Pre synchronization: Prepare for actual synchronization, i.e. authentication, authorization ,determination of device characteristics
Synchronization: Local IDs are mapped to Global IDs, and data are exchanged.
Post synchronization: Clean up tasks are performed, update the mapping tables.
28. List the characteristics of IrDA.
Frequency band
Security
Transmitting capabilities
Bandwidth
Speech
29. List the basic security concepts involved in pervasive computing applications.
Identification
Authentication
Authorization
Transaction authorization
Digital signature endorsed by password
Transaction authentication number
Non repudiation
30. List the Challenges of device management in Pervasive Computing?
Tracking the device location
Device user relationship
Version control of devices and software that are out in the field
Software updates of existing devices
Installation of new software on existing devices.
Part B
- Describe the principles of pervasive computing with examples.
<First list the principles one by one>
Decentralization
Diversification
Connectivity
Simplicity
<Then explain each topic in connection to pervasive computing >
Decentralization
Distributed systems
Having logic, database, control in a distributed style, not in a single machine-centralized controller.
Synchronizing Information
Use applications on mobile devices and related data to be updated with networked systems
Managing Applications
For example cellular phone network, tracking and billing are very essential processes. Scalable managing application server and high end backend systems are deployed.
Diversification
Targeting specific needs
Clear move from universal computers(all in one) to diversified devices challenging performance, price and functionality.
Diversified devices areaim at best meeting the requirements of a specific group of users for a specific purpose.
Four alternatives to surf the web
Several tools might have some overlap in functionality:preferred tools for each specific purpose.
- One can use internet screen phone at home and enjoy multimedia effects.
- For mobile internet access, a wireless connected handheld computer is the choice even it has less graphical capabilities and small display.
- Third one is WAP phone, a ultra-light and very handy and can’t enjoy multimedia effects.
- PC with single OS with multiple functionalities and work load can be used for the same purpose ., but memory requirement is high when compared to others…such case windows CE version can be employed which requires a feasible memory capacity.
Managing the Diversity
It’s a challenge to manage device diversity, since each with different capabilities. The delivery platform as many difficulties in providing common applications.
For example in case of e- shopping website in a WAP phone, user cannot see the images representing services or objects.
Connectivity
A vision of boundless connectivity
Manifold devices are seamlessly integrated in an IT world without boundaries.
Exchange information through infra-red, datacable, Bluetooth.
Cellular phones with GSM, CDMA also involved in the environment.
Real life obstacles
Platform specific issues: obstacle for application and information exchange.
Devices with different persistent storage ranging from kilobytes(smart card) to gigabytes(multimedia systems)
Different OS and variety of processors put various restrictions.
Agreeing on common standards
Achieving connectivity and interoperability between devices is possible only when the objects are supposed to follow common standards (ISO-OSI, etc…).
When it comes to application data exchange across devices, JAVA is the path finder, since JAVA is platform independent.
Representation of data in variety of devices of multiple characteristics is resolved by the introduction of XML.
Concepts like jini or UPnP help devices to discover suitable services in a network to which they can delegate specific tasks. Automatic reconfiguration based on self-attach and detach (plug & play capability) implies self-explained and easy usage of network-connected utilities. With jini, networks turn into a dynamic and distributed system.
Simplicity
Device operations need to be easy, so that the user shall feel comfort with his needs.
User Interfaces should not have complicated operations.
At present “one touch “keys are designed for user easiness.
Touch screen with relevant symbols, images help user to interact well.
Handwriting recognition, speech recognition enabled interfaces, simplifies the user actions and makes him comfort with the system.
- With neat diagram explain Biometrics system.
BIOMETRICS is not limited to fingerprint, it involves face recognition, DNA, Palm print, hand geometry, irisrecognition, which has largely replaced retina, and odor/scent.
Related to the behavior of a person. Examples include, but are not limited totyping rhythm, gait, and voice. Some researchers have coined the termbehaviometrics for this class of biometrics.
In this system, the user characteristic (fingerprint, voice…) is captured using a specific sensor and its features are extracted to have a template .This template will be stored in the database for reference.
In a simple system, when a user provides the characteristic like fingerprint, the system extracts the features and compares it with the template stored earlier. If it is same the system allows him.
Generation of reference value at the time of extracting features and template designing and also at the time of comparison is subject to distortion.so there is always a possibility of biometric system authentication failure.
FAR: False Acceptance Rate-probability that the system accepts the wrong user.
FRR: False Rejection Rate-probability that the system rejects correct user.
So we can have a combination of both SIM card (user id module) and bio-feature in the system.
Here the FAR, FRR are very very low.
Key features of Biometrics:
•Universality – each person should have the characteristic.
•Uniqueness – is how well the biometric separates individuals from another.
•Collectability – ease of acquisition for measurement.
•Performance – accuracy, speed, and robustness of technology used.
•Acceptability – degree of approval of a technology.
- Explain the Palm OS architecture and development cycle
Palm OS
Most successful OS for PDA
Available with palm,handspring,IBM, Sony..
Optimized limited number of features
Low (memory,CPU usage):leads to longer battery life
Version 3.5(256 colors)
Version 4.0(65k colors, Bluetooth support)
OS features:
User management: used as personal device with single user operating system
Task management: one application at a timeand one can call other application
Power management:sleep/doze/running mode
OS size:V3.5/1.4 MB/runtime memory:64kb
User Interface: handwriting recognize/single button access
Memory management: dynamic heap/storage
Development cycle
Supports c, c++(c almost/c++ a little)\
C-best choice for performance critical applications
C-simple and fast, Extensive system library
Free SDK based on GNU for windows,Mac,Linux
Commercial IDE –Metro codewarrior (editor, compiler,debugger,visual graphical user interface constructor)
Palm applications are event-driven and synchronous
Several VM available KVM (Sun),J9 (IBM),WabaVM(Wabasoft)
Palm emulator: emulates a Palm H/W in a PC
Code is compiled –run-debug-edit-compiled
Until a ultimate program is achieved
Finalized code is downloaded to Palm from the emulator
4. Write short notes on
a.J2EE
In today's heterogeneous environment, enterprise applications have to integrate services from a variety of vendors with a diverse set of application models and other standards. They require bringing together a variety of skill sets and resources, legacy data and legacy code.
The J2EE platform breaks the barriers inherent between current enterprise systems. The unified J2EE standard wraps and embraces existing resources required by multitier applications with a unified, component-based application model.
Key features:
Java™ Database Connectivity (JDBC™) API
Transaction Service
Java Naming and Directory Interface™ (JNDI) API
Java™ Message Service (JMS) API
JavaMail™ API
b.J2ME
J2ME stands for Java 2 Platform, Micro Edition. The edition is targeted at small, standalone or connectable consumer and embedded devices. The J2ME technology consists of a virtual machine and a set of APIs suitable for tailored runtime environments for these devices. The J2ME technology has two primary kinds of components – configurations and profiles.
The configuration and technologies available for pervasive devices based on J2me:
Connected device configuration
Connected , Limited device configuration