13 February 2017

Mobile Computing Viva Unit wise Short Questions and Answers PDF

Source: Credits goes to the faculty and staff of Pavendar Bharathidasan Institute of Information Technology.

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Cellular Wireless Networks – GSM – Architecture – Protocols – Connection Establishment – Frequency Allocation – Routing – Mobility Management – Security – GPRS
1. What is mobile computing? 
Mobile computing is a technolgythat allows transmission of data, via a computer,Without having to be connected to a fixed physical link.

2. What is Mobility? 
A person who moves
Between different geographical locations Between different networks Between different communication devices Between different applications A device that moves
Between different geographical locations Between different networks

3. What is guard space? 
Guard spaces are needed to avoid frequency band overlapping is also called channel interference.

4. What is multiplexing? 
Multiplexing is transmitting multiple signals over a single communications line or computer channel. The two common multiplexing techniques are FDM, which separates signals by modulating the data onto different carrier frequencies, and TDM, which separates signals by interleaving bits one after the other.

5.What is FDM 
FDM is frequency division multiplexing which describes schemes to subdivide the frequency dimension into several non overlapping frequency bands.

6.What is hopping sequence? 
Transmitter and receiver stay on one of the channels like and TDM.The pattern of channel usage is called the hopping sequence,

7. What is dwell time? 
The time spend on a channel with a certain frequency is called the dwell time

8. What are the two types of hopping sequence? 
1) Slow hopping 2) Fast hopping

9. What are the advantages of cellular systems? 
The advantages of cellular systems are,
Higher capacity Less transmission power Local interface only Robustness

10. What are digital cellular networks? 
Digital cellular networks are segment of the market for mobile and wireless device which are growing most rapidly.

11. What are the disadvantages of cellular systems? 
The advantages of cellular systems are, _ Infrastructure needed _ Handover needed _ Frequency planning

12. What is GSM? 
GSM is group special mobile.GSM is the successful digital mobile telecommunication system in the world today.

13. What is authentication centre?
As the radio interface and mobile stations are particularly vulnerable a separate AuC has beendefined to protect user identity and data transmission. The AuC contains the algorithms for authentication as well as the keys for encryption and generates the values needed for user authentication in the HLR. The AuC may, in fact, be situated in a special protected part of the HLR.

14. What is called burst? 
Data is transmitted in small portions is called bursts,

15. What are the basic groups of logical channels? 
GSM specifies 2 basic groups of logical channels, _ Traffic channels _ Control channels

16. Define MSC? 
MSC is mobile services switching center.MSC are high performance digital ISDN switches.

17. What is GPRS? 
GPRS is general pachet radio service.

18. Specify the steps perform during the search for a cell after power on?
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19. Explain about transparent mode? 
The transparent mode transfer simply forwards MAC data without any further processing. The system then has to rely on the FEC which is always used in the radio layer.

20. What are the basic classes of handovers? 
UMTS has 2 basic classes of handovers, Hard handover Soft handover

21. What is GPRS? 
GPRS is general packet radio service.

22. What are the control channel groups in GSM? 
The control channel groups in GSM are:
• Broadcast control channel (BCCH).
• Common control channel (CCCH).
• Dedicated control channel (DCCH).

1. Explain GSM architecture?
2. Explain GSM System architecture?
3. Explain briefly about Multiplexing?
4. Explain medium access control?
5. Write a short note on Cellular Wireless Networks
6. Explain the Security mechanism implemented in GSM.
7.Explain the GPRS system.

Wireless LANs and PANs – IEEE 802.11 Standard – Architecture – Services –Network – HiperLAN – Blue Tooth- Wi-Fi – WiMAX

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6. Write a short note on Wi-Fi andWiMAX.

Mobile IP – DHCP – AdHoc– Proactive and Reactive Routing Protocols – Multicast Routing.
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Mobile TCP– WAP – Architecture – WWW Programming Model– WDP – WTLS – WTP –
WSP – WAE – WTA Architecture – WML – WMLScripts.
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6.Write a short notes on mobile TCP.

Pervasive computing infrastructure-applications- Device Technology - Hardware, Human- machine Interfaces, Biometrics, and Operating systems– Device Connectivity –Protocols, Security, and Device Management- Pervasive Web Application architecture-Access from PCs and PDAs - Access via WAP
1. What is Pervasive computing?
Pervasive computing is a rapidly developing area of Information and Communications Technology (ICT). The term refers to the increasing integration of ICT into people’s lives and environments, made possible by the growing availability of microprocessors with inbuilt communications facilities.

2. What are the three areas of pervasive computing technologies?
Pervasive computing involves three converging areas ofICT: computing (‘devices’), communications(‘connectivity’) and ‘user interfaces’.

3. Give the history of pervasive computing.
Pervasive computing is the third wave of computingtechnologies to emerge since computers first appeared:
• First Wave - Mainframe computing era: one computershared by many people, via workstations.
• Second Wave - Personal computing era: one computerused by one person, requiring a conscious interaction.Users largely bound to desktop.
• Third Wave – Pervasive (initially called ubiquitous)computing era: one person, many computers. Millionsof computers embedded in the environment, allowingtechnology to recede into the background.

4. Give the applications of pervasive computing.
Healthcare, home care, transport andenvironmental monitoring are among the most frequently cited.

5. List the devices used in pervasive computing.
PCS devices are likely to assume many different forms and sizes, from handheld units (similar to mobile phones) to near-invisible devices set into ‘everyday’ objects (like furniture and clothing). These will all be able to communicate with each other and act ‘intelligently’. Such devices can be separated into three categories:
• sensors: input devices that detect environmental changes, user behaviours, human commands etc;
• processors: electronic systems that interpret and analyse input-data;
• actuators: output devices that respond to processed information by altering the environment via electronic or mechanical means. For example, air temperature control is often done with actuators.

6. What is device connectivity?
Pervasive computing systems will rely on the interlinking of independent electronic devices into broader networks. This can be achieved via both wired (such as Broadband (ADSL) or Ethernet) and wireless networking technologies (such as WiFi or Bluetooth), with the devices themselves being capable of assessing the most effective form of connectivity.

7. Define user interface in Pervasive computing. 
User interfaces represent the point of contact between ICT and human users. For example with a personal computer, the mouse and keyboard are used to input information, while the monitor usually provides the output.

8. List the different forms of human- computer interaction.
• Active
• Passive
• Coercive

9. How is privacy, security and safety defined in pervasive computing?
Pervasive computing systems may have implications for privacy, security and safety, as a result of their ability to:
• gather sensitive data, for example on users' everyday interactions, movements, preferences and attitudes, without user intervention or consent;
• retrieve and use information from large databases/archives of stored data;
• alter the environment via actuating devices.

10.List the drawback of pervasive computing over health.
Non-ionising radiation is a by-product of the wireless signals that are likely to be used to connect pervasive computing devices into broader networks.

1. Write a short note on pervasive computing infrastructure and also give its applications 
2. Explain the role of human machine interaction in pervasive computing. 
3. Write a short note on device connectivity 
4. Write a short note on security of pervasive computers 
5. Write short note on pervasive web application architecture.

* To get Clear; figures / diagrams, tables / values, answers / explanations and more, download the Mobile Computing Viva Unit wise Short Questions and Answers PDF.