Wireless communication networks are generally implemented using electromagnetic waves to transmit information over the air without wires. Key aspects of wireless communication discussed in the document include: 1. Maxwell's equations laid the foundation for understanding electromagnetic waves, which are used to transmit signals wirelessly. 2. Wireless signals are transmitted using antennas that emit sinusoidal waves at radio frequencies like 900MHz, 2.4GHz, and 5GHz across different wireless standards. 3. Wireless networks offer mobility, lower installation costs than wired networks, and increased reliability but also face challenges like interference, security issues, and potential health risks from radio signals.

1. Wireless Communication
Prof. Dr. S. Swapna Kumar
Dept. of Electronics and Communication Engg.
Vidya Academy of Science and Technology, Thalakkottukara, Thrissur,
Kerala- 680501, India
drsswapnakumar@gmail.com

2. Michael Faraday and James Clerk Maxwell,
inventors of the field concept in electricity and magnetism.
Maxwell’s Equations

3. Wave Propagation
electric
field
magnetic
field
Notice that the electric and magnetic fields are at right angles to one another!
Emitted by sinusoidal current running through a wire (transmitting antenna)

4. What is Frequency?
• Wave
vocabulary
– Amplitude
– Frequency
– Period
– Wavelength
– Bandwidth

c
f Name 900 Mhz 2.4 Ghz 5 Ghz
Range 902 - 928 2.4 - 2.4835 5.15 - 5.35
Bandwidth 26 Mhz 83.5 Mhz 200 Mhz
Wavelength .33m / 13.1” .125m / 4.9” .06 m / 2.4”

5. Radio Frequency (RF) Spectrum

6. Transmission Media
7.6

7. GUIDED MEDIA

8. WIRELESS
• Any type of electrical or electronic operation accomplished without use of
wires.
• Wireless connections use air to connect sending and receiving devices
COMMUNICATION
Sending
device message
Connection
device
Communication
channels
Connection
device message
Receiving
device
• It is transmission of signals i.e. sending of electromagnetic waves by
electronic transmitters
• Channel is a division in transmission medium

9. WHAT IS WIRELESS
COMMUNICATION?
• Transmitting/receiving voice and data using
electromagnetic waves in open space.
• The information from sender to receiver is carried
over a well defined frequency band(channel).
• Each channel has a fixed frequency bandwidth &
capacity(bit rate).
• Different channels can be used to transmit
information in parallel and independently.

10. EARLY WIRELESS WORK
Early inventors –Alexander Graham Bell, Gaglielmo
Marconi and John Logie Baird
• In 1878, David E Hughes induced electromagnetic
waves
• In 1888, Thomas Alva Edison used a vibrator
magnet for induction transmission, gave system of
signals.

11. History: Timeline
1894 –
experiments
began with
Hertzian Waves
1896 – Wireless
Telegraph &
Signal Company
established
1901 – first
trans-Atlantic
signal received
1905 – first
distress signal
successful using
Morse Code
1919 – RCA
incorporated
1939-1945 – WWII
US Military initiates
radio data
transmission
technology
1971 –
ALOHANET
experiment,
first wireless
LAN
1973 –
Motorola
creates first
mobile cellular
telephone
1983 – America
enters cellular
telephone
market
1987 – FCC
encourages use
of 800Mhz
spectrum
1990 – IEEE
creates work
group to
establish
wireless LAN
standards
1997 – 802.11
established as
wireless LAN
standard

12. Why Deploy Wireless?
• Unlicensed bands.
• Global coverage
• No bunch of wires running.
• Cost savings over wire line.
• Can not run wire to
locations needed.
• Stay connected, flexibility to
connect multiple devices.
“Do I really need all
of that wire?”
Nightmare jumble of
cables

13. “Wireless Communication Waves”
Wireless Communication networks are generally
implemented with some type of remote information
transmission system that uses electromagnetic waves.

14. Propagation methods

15. How communication takes place
Transmitting signal
Received signal
satellite
Transmitting
antenna
Receiving
antenna

16. CURRENT WIRELESS SYSTEMS
• CELLULAR SYSTEM
• WIRELESS LANs
• SATELLITE SYSTEM
• PAGING SYSTEM
• PANs(BLUETOOTH)

17. TYPICAL FREQUENCIES
• FM RADIO 88 MHZ
• TV BROADCAST 200 MHZ
• GSM PHONES 900 MHZ
• GPS 1.2 GHZ
• PCS PHONES 1.8 GHZ
• BLUETOOTH 2.4 GHZ
• Wi-Fi 2.4 GHZ

18. WIRELESS NETWORKS
Wireless network is a network set up by using radio signal frequency to
communicate among computers and other network devices. Sometimes
it’s also referred to as WiFi network or WLAN.
• Wireless devices
– Distance: 300 feet (90 meters)
– Bandwidth: 54 Mbps
– Can also include Voice over IP (VoIP)
Types:-
 Digital networks –consists routers that route data
 Analog networks – consists switches establishing connections

19. The Wireless Landscape

20. The Wireless Landscape

21. 21
Advantages of Wireless
Networking
• Mobility
• Easier and less expensive installation
• Increased reliability
• Disaster recovery

22. 22
Disadvantages of Wireless Devices
• Wireless communication disadvantages
– Radio signal interference
– Security issues
– Health risks

23. FUTURE
Major role in development of technology
High speed data transfer
Data transfer over large area or distance
Eco friendly and non-hazardous ways have to be found
out
Has to be made more secured

24. To Be Continued….(Convergence)

25. The Institute of Electrical and
Electronics Engineers = IEEE
IEEE
Journals
Conference
Proceedings
Standards
IBM Journal
eBooks
E-learning
Library

26. Thank You!!