Mobile computing allows users to access information and computing resources anywhere without being restricted to a fixed location. It utilizes wireless technologies like cellular networks, WiFi, and satellites to connect devices. Common mobile devices include laptops, tablets, and phones. Mobile computing enables various applications in fields like healthcare, retail, and travel. However, it faces challenges from limited bandwidth, security issues, device power consumption, and potential health effects of wireless transmissions.

1. MOBILE AND WIRELESS
COMPUTING

2. Mobile Computing
 Also called nomadic, tetherless, wireless,
ubiquitous, remote computing
 User does not need to maintain a fixed
position in the network
 Useful for persons who travel away from
their primary work place

3. Mobile Computing
 Mobile computing is "taking a computer
and all necessary files and software out
into the field.“
 Mobile commerce is any transaction,
involving the transaction having
monetary value, which is initiated and/or
completed by using wireless electronic
device such as mobile phones, PDAs,
pagers etc. and mobile telecommunication
network. It is subset of e-commerce.

5. Mobile & Wireless Computation
 Wireless & Mobile are not synonymous
 Wireless
 Isa transmission or information transport
method that enables mobile computing
 Communication is without wires
 MobileComputing focuses on the
applications side .
 Ability to compute no matter where the
user is
 Infrared, cellular, radio waves, microwave,
satellite services

6. Mobile Computing Framework
 Wireless delivery technology
 Mobile Information Access Devices
 Mobile Data Internetworking standards
and equipment
 Mobile computing based business
applications

7. Wireless delivery technology
1. Radio-Based Systems
2. Infrared or mobile based computing

8. Radio-Based Systems
 Thesesystems use radio frequency (RF)
signals that range from 100 KHz to 20
GHz
 RF communication is of 3 types
 One way
 Two way
 Local way

9. Cont…
 Radio-Basedservices can be grouped in
two main categories
1. Land Based
 Cellular Communications
 Wireless Packet Data networks(GPRS)
1. Satellite Based(Satellite Networks)
 Very Small Aperture Terminals(VSATs)
 Paging and Satellite networks

10. Cellular Communications
 In cellular system, the area of coverage is
divided in to hexagonal cells that overlap
at the outer boundaries
 Communication takes place with the help
of transceivers
 A signal from the handset goes to nearest
cell through telephone lines
 The size of cell is 2-10 miles
 Working

11. Wireless Packet data networks
 Uses packet techniques for transferring
data
 Packet radio is a communication method
used to transmit packets of data over
network via RF signals
 These services were designed with data
only in mind
 Working

12. Satellite Networks
 Used for global communication(broadcast)
 Useful where data need to be dispersed or
gathered from many remote nodes and
end to end delay is not of concern
 Cost effective
 Reliable
 Suitable for remote areas where poor or
non existent phone services
 Disadv: poor choice for systems where a
high degree of security is required

13. Very small aperture
terminals(VSATS)
 Uses a large no. of small dishes called
VSATS for outlying nodes and one central
hub with a big dish.
 This approach causes additional delay
 Typically used by the organizations that
require data or voice communication
between sites distributed over a wide
geographical area

14. Paging and satellite networks
 Oldest form of mobile communication
(1949)
 One way mobile communication services
 Wireless communications
 Working
 Used for news, sports, weather, stock
information etc at scheduled intervals

15. Infrared or light based mobile
computing
 Works by sending pulses of light from a
LED to a photo sensor that diverts signals
 Computing devices can send as well as
receives signals
 Types of infrared equipments
 Low speed (115 kbps- 250 kbps)
 High speed (about 1.25 mbps)
 There should not be any physical
obstructions between sending and
receiving
 Cost effective

16. Mobile Information Access
Devices
 Portable Computers
 Laptops,Notebooks,Handhelds
 Hybrid Pen Computers
 Personal Digital Assistants(PDAs)

17. Mobile Data Internetworking
standards and equipment
Reasons for analog to digital transition:
 Limited available bandwidth
 Overcrowding
Current analog system divides the available
spectrum into 30 KHz wide channels.

18. Cont…
Technologies for multiple Channel Access
 CDMA(Code Division Multiple Access)
 Isa wideband spread-spectrum technology
 Uses specialized codes as the basis of
channelization(division of the frequency
spectrum into multiple channels)
 TDMA(Time Division Multiple Access)
 GSM(Global
System for Mobile
Communications ) is a type of TDMA
 Addsa time sharing of 3 users on each
frequency)

19. Mobile computing based business
applications
It is resulting in two changes:
 Remote Communications
 Remote data access
Applications:
 Health care
 Retail
 Field service
 Traveling professionals
 Sales and service

20. Cont…
Applications:
 Members of work groups
 Stock and commodity training

21. Technical and other limitations of
mobile computing
 Insufficientbandwidth
 Security standards
 Power consumption
 Transmission interferences
 Potential health hazards
 Human interface with device
(http://en.wikipedia.org/wiki/Mobile_comput
ing)

22. Mobile Data Internetworking
standards and equipment
 Consider a room (channel) in which people wish to
communicate with each other.
 To avoid confusion,
 people could take turns speaking (time division),
 speak at different pitches (frequency division),
 or speak in different directions (spatial division).
 In CDMA, they would speak different languages. People
speaking the same language can understand each other,
but not other people. Similarly, in radio CDMA, each
group of users is given a shared code. Many codes
occupy the same channel, but only users associated with
a particular code can understand each other.
http://www.broadbandreports.com/faq/5668