1. Presentation Topic:
The Different Modes Of Data
Communication
Presented by:
Simranjeet Kaur (94972346431)
Simranjeet Singh (94972346433)
Sunil Singh (94972346445)
Tafadzwa Gonera (94972346447)

2. Contents
• Introduction the data communication
• Protocol models of data communication
• Communication channels
• Wired communication
• Wireless communication
• Conclusion

3. Definition of data communication
• It is the physical transfer of data (a digital bit
stream) over a point to point to multipoint
communication channel.
• Examples of such: optical fibre, copper wires,
wireless communication channels ,etc.
• Data is represented as an electromagnetic
signal, such as voltage, microwave, etc.

4. Protocol models
• The Open Systems Interconnection (OSI
Model) is a way of subdividing a
communications system into smaller parts
called layers
• A layer is a collection of conceptually similar
functions that provide services to the layer
above it and receives services from the layer
below it

5. TCP/IP Model
• It is a description framework for computer
network protocols created in the 1970s by
DARPA
• The TCP/IP model, or Internet Protocol Suite
describes a set of general design guidelines
and implementations of specific networking
protocols

6. Definition of communication channel
• It refers to either a physical transmission such
as a wire or to a logical connection over a
multiplexed medium such as a radio channel
• A channel is way to convey a message
• Modes of transmission are: simplex, half
duplex or full duplex
• Types of transmission are: parallel and serial

7. Wired communication
• A type of LAN technology which is based on a
special type of cable which is used to transfer
data
• The maximum data transfer rate of this
technology is 10Mbps
• The cables used to configure the network are
special. Examples are Ethernet and wired LAN

8. Coaxial cables
• It is an armored cable with sheathed plastic
that contains two concentric conductors or
wires
• It is used primarily for TV standard-definition
connection
• It is used to implement computer networks
like Ethernet
• It is also used to connect radio networks

9. A diagram of a coaxial cable:

10. Advantages
• It has sufficient frequency to support multiple
channels
• Each of the multiple channels offers
substantial capacity
• Inner conductor is in a Faraday shield,
therefore noise immunity is reduced

11. Disadvantages
• Signal leakage
• Imperfect shield of coaxial cable can causes
visible or audible interference
• External current sources like switched-mode
power supplies create a voltage across the
inductance
• Common mode current occurs when stray
currents in the shield flow in the same
direction as the current

12. Fiber optic cables
• The fiber optical consists of several thin fibers
of glass or plastic of 50 to 125 micrometers of
diameter
• They are used in fiber optic communications
which permit transmission over longer
distances and at higher bandwiths

13. A diagram of fiber optic cable:

14. Advantages
• Data transmission is incredibly fast
• Fiber optic cables are not susceptible to RF
(Radio Frequency) interference
• Fiber optic cables can transmit data over
exceptionally long distances with much data
loss
• Wiretapping is more difficult compared to
electrical connections

15. Disadvantages
• Fiber optic cabling can cost more than double
what a typical broadband connection costs
• Fiber optic connections are not available in
many areas. Currently, this is one of the
biggest disadvantages

16. Twisted pair cables
• Twisted pair cabling is a type of wiring in
which two conductors (the forward and return
conductors of a single) are twisted together to
cancel electromagnetic interference
• Unshielded twisted pairs (UTPs) are mainly
used in Ethernet and telephone systems
• They are also used for indoor applications

17. A diagram of twisted pair cable:

18. Advantages
• It is thin, flexible cable that is easy to string
between walls
• More wires can be run through the same
wiring ducts.
• UTP costs less per meter/foot than any other
type of LAN cable

19. Disadvantages
• UTPs susceptibility to electromagnetic
interference greatly depends on the pair
twisting schemes
• In video applications that send information
across multiple parallel signal wires, twisted
pair cabling can introduce signaling delays
known as skew which results in color defects
and ghosting

20. Wireless communication
• Wireless communication uses radio
frequencies (RF) or infrared (IR) waves to
transmit data between devices on LAN
• Key components are a wireless hub, or access
point used for signal distribution
• Wireless signals are electromagnetic waves
that can travel through a vacuum of outer
space

21. Bluetooth
• It is a proprietary open wireless technology
standard for accessing data over short
distances
• Bluetooth uses short wavelength radio
transmission to create PANs
• Range of data transfer is power dependent i.e.
100m,10m and 1m but ranges may vary

22. Uses
• Wireless control of and communication
between a mobile phone and a hands free
headset
• Wireless networking between PCs in a
confined space
• Wireless communication with PC IO devices
• Transfer of files, contact details, calendar
appointment and reminders between devices

23. Advantages
• It has a high level of compatibility among
devices
• It will connect to devices that are not of the
same model
• It almost always avoids interference from
other wireless devices
• It is doesn’t a line of sight connection it
provides ranges of up to 100meters

24. Disadvantages
• Infrared has data rates of up to 4 Mbps while
Bluetooth only offers 1 Mbps
• The greater range and radio frequency (RF) of
Bluetooth makes it susceptible to interception
and attack

25. WiMAX
• Worldwide Interoperability for Microwave
Access is a telecommunications protocol that
provides fixed and mobile internet access
• It provides up to 40 Mbps with IEEE 802.16m
expected to offer up to I Gbps
• It’s a standards based technology enabling the
delivery of last mile wireless broadband access

26. Uses
• Provides portable mobile broadband
connectivity across cities and countries
• Provides a wireless alternative to cable and
DSL for last mile broadband access
• Provides data, telecommunication (VoIP) and
IPTV services
• Provides a source internet connectivity as part
of a business continuity plan

27. Advantages
• A single station can serve hundreds of users
• Much faster deployment of new users
comparing to wired networks
• Speed of 10Mbps at 10kilometers within line-
of-site
• It is standardized, and the same frequency
equipment should work together

28. Infrared
• (IR) Infrared Light is electromagnetic radiation
with a wavelength between 0.7 and 300
micrometers, which equates to a frequency
range between approximately 1 and 430THz
• IR wavelengths are longer than that visible
light, but shorter than that of terahertz
radiation microwaves

29. Uses
• It is employed in short range communication
among computer peripherals and PDAs
• It is used for remote controls to command
appliances

30. Advantages
• Low power requirements: therefore ideal for
laptops, PDAs and cellphones
• Low circuitry cost
• Installation is easy because no proprietary
hardware is needed
• Higher security
• High noise immunity

31. Disadvantages
• Performance drops off with longer distances
• It is weather sensitive: data transmission is
poor is direct sunlight, rain, fog, dust ,etc.
• Data rate transmission is lower than typical
wired transmission
• Data transmission is possible in the line of
sight: transmitters and receivers should be
aligned

32. Wi-Fi
• Wi-Fi is a wireless technology that uses radio
waves to provide wireless high-speed internet
and network connections
• Wi-Fi alliance defines Wi-Fi as any “wireless
local area network (WLAN) products that are
based on the IEEE 802.11 standards”
• The cornerstone of any wireless network is an
access point (AP)

33. Advantages
• Wi-Fi allows the deployment of LANs without
wires for client devices
• Deployment of WLANs reduces the costs of
network deployment and expansion
• Wi-Fi is becoming widespread and easily
accessible in the corporate infrastructures
• Different brands of access points and client
network interfaces can interoperate

34. Advantages
• Wi-Fi Alliance are backwards compatible
• Current version Wi-Fi protected access
encryption is considered secure
• Powers saving mechanisms such as WMM
power save improve battery operation

35. Disadvantages
• Spectrum assignments and operational
limitations are not consistent worldwide
• The most common wireless encryption-
standard, Wired Equivalent Privacy is not
secure
• Mobile use of Wi-Fi over wider range is limited
• Congestion

36. Conclusion
• Wired technology is more secure, reliable,
cheaper and has higher data transmission
rates over wireless technology but one huge
advantage that has made wireless technology
popular is mobility.

37. The End