about wireless communication in detail which will help you by abhishek mahajan

1. SHREEJEE INSTITUTE OF
TECHNOLOGY AND MANAGEMENT
Wireless Communication
• Guided By:- Mr.Prakash
Singh Panwar
• By:- Krishna Rathor
• EC BRANCH 1ST YEAR

2. WHY WIRELESS COMMUNICATION?
Freedom from wires.
No bunch of wires running from here and there.
“Auto Magical” instantaneous communication without
physical connection setup e.g.- Bluetooth, Wi-Fi.
Global coverage
Communication can reach where wiring is infeasible
or costly
E.g.- rural areas ,buildings,battlefield,outerspace.
Stay connected , flexiblity to connect multiple devices.

3. 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 channel.
• Each channel has a fixed frequency bandwidth &
capacity(bit rate).
• Different channels can be used to transmit information
in parallel and independently.

4. 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

5. How communication takes place?
Transmitting Signal
Received Signal
Satellite
Transmitting
Antenna
Receiving
Antenna

6. TYPES OF WIRELESS COMMUNICATION?
RADIO TRANSMISSION:- easily generated, Omni-directional ,
travel long distance , easily penetrates buildings.
• PROBLEMS:- frequency dependent , relatively low
bandwidth for data communication , tightly licensed by
government.
MICROWAVE TRANSMISSION:- widely used for long distance
communication , relatively inexpensive.
• PROBLEMS:- don’t pass through buildings , weather and
frequency dependent.

7. TYPES CONTINUED….
INFRARED AND MILIMETER WAVES:-
Widely used for short range communication , unable to
pass through solid objects , used for indoor wireless
LANs , not for outdoors.
LIGHT WAVE TRANSMISSION:- unguided optical signal
such as laser , unidirectional , easy to install , no license
required.
PROBLEMS:- unable to penetrate rain or thick fog , laser
beam can be easily diverted by air.

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

9. What is cellular system?
• Definition
Wireless communication technology in
which several small exchanges (called cells)
equipped with low-power radio antennas
(strategically located over a wide
geographical area) are interconnected
through a central exchange. As
a receiver (cell phone) moves from one
place to the next, its identity, location, and
radio frequency is handed-over by one cell
to another without interrupting a call.

10. Cont.…
• Communication between the base station and mobiles is defined by the standard
common air interface (CAI)
– Forward voice channel (FVC): voice transmission
from base station to mobile
– Reverse voice channel (RVC): voice transmission
from mobile to base station
– Forward control channels (FCC): initiating mobile
call from base station to mobile
– Reverse control channel (RCC): initiating mobile
call from mobile to base station

11. Cellular Telephone Systems
• Provide connection to the PSTN for any user location within the radio
range of the system.
• Characteristic
– Large number of users
– Large Geographic area
– Limited frequency spectrum
– Reuse of the radio frequency by the concept of “cell’’.
• Basic cellular system: mobile stations, base stations, and mobile switching
center.

12. Cordless Telephone System
• Cordless telephone systems are full duplex communication systems.
• First generation cordless phone
– in-home use
– communication to dedicated base unit
– few tens of meters
• Second generation cordless phone
– outdoor
– combine with paging system
– few hundred meters per station

13. Evolution of Mobile Radio Communications
• Major Mobile Radio Systems
– 1934 - Police Radio uses conventional AM mobile communication system.
– 1935 - Edwin Armstrong demonstrate FM
– 1946 - First public mobile telephone service - push-to-talk
– 1960 - Improved Mobile Telephone Service, IMTS - full duplex
– 1960 - Bell Lab introduce the concept of Cellular mobile system
– 1968 - AT&T propose the concept of Cellular mobile system to FCC.
– 1976 - Bell Mobile Phone service, poor service due to call blocking
– 1983 - Advanced Mobile Phone System (AMPS), FDMA, FM
– 1991 - Global System for Mobile (GSM), TDMA, GMSK
– 1991 - U.S. Digital Cellular (USDC) IS-54, TDMA, DQPSK
– 1993 - IS-95, CDMA, QPSK, BPSK

14. Example of Mobile Radio Systems
• Examples
– Cordless phone
– Remote controller
– Hand-held walkie-talkies
– Pagers
– Cellular telephone
– Wireless LAN
• Mobile - any radio terminal that could be moves during operation
• Portable - hand-held and used at walking speed
• Subscriber - mobile or portable user

15. a
• Classification of mobile radio transmission system
– Simplex: communication in only one direction
– Half-duplex: same radio channel for both transmission and reception (push-to-
talk)
– Full-duplex: simultaneous radio transmission and reception (FDD, TDD)
• Frequency division duplexing uses two radio channel
– Forward channel: base station to mobile user
– Reverse channel: mobile user to base station
• Time division duplexing shares a single radio channel in time.
Forward Channel
Reverse Channel

16. Wireless local area
network(WLAN)
• WLAN connect local computers
• Range (100 m) confined region
• Break data into packets
• Channel access is shared
• Backbone internet provides best service
• Poor performance in some application like
videos
• Low mobility

17. Satellite system ?
• Global coverage
• Optimized for good transmission
• Expensive base stations.
• Voice and data transmission
• Telecommunication application
• GPS , global telephone connection
• TV broadcasting , military , weather
broadcasting

18. Paging system ?
• Broad coverage for short messages
• Message broadcast from all base stations
• Simple terminals
• Optimized for one way transmission
• Answer back hard
• Overtaken by cellular

19. Paging Systems
• Conventional paging system send brief
messages to a subscriber
• Modern paging system: news headline, stock
quotations, faxes, etc.
• Simultaneously broadcast paging message
from each base station.
• Large transmission power to cover wide area.

20. Modes of wireless communication!
• Bluetooth
• NFC (Near Field Communication)
• Wi-Fi
• Lifi

21. What is Bluetooth?
• Bluetooth is a method for data
communication that used short range radio
links to replace cables between computers
and their connected units.
• Named on – Danish king harald Bluetooth
• Developed in Scandinavia.

22. How does Bluetooth works?
• Bluetooth networking transmits data via low-
power radio waves. It communicates on a
frequency of 2.45 gigahertz.
• Bluetooth doesn't require line of sight
between communicating devices.
• Bluetooth can connect up to eight
devices simultaneously.
• Bluetooth uses a technique called spread-
spectrum frequency hopping

23. Bluetooth is essentially a networking
standard that works at two levels:
• It provides agreement at the physical level --
Bluetooth is a radio-frequency standard.
• It provides agreement at the protocol level,
where products have to agree on when bits
are sent, how many will be sent at a time, and
how the parties in a conversation can be sure
that the message received is the same as the
message sent.

24. Applications of Bluetooth!
• Bluetooth speakers
• Bluetooth headphones
• Cable less connections to the printers
• Bluetooth keyboard

25. What is NFC?
• NFC is a short-range high frequency wireless
communication technology that enables the
exchange of data between devices over about
a 10 cm distance.
• It allows devices to establish peer-to-peer
radio communications, passing data from one
device to another by touching them or putting
them very close together.

26. How NFC works?
• NFC came out of RFID. RFID, or radio-frequency
identification, is the technology used by superstores to
keep track of goods, it uses electromagnetic induction
in order to transmit information. NFC is similar
technology, but standardized for consumer
smartphones.
• NFC is a means of sending data over radio waves. In
that sense it is similar to Wi-Fi or Bluetooth, but unlike
those protocols (and like RFID) NFC can be used to
induce electric currents within passive components as
well as just send data. And it is faster than Bluetooth.

27. Benefits over Bluetooth..
• The significant advantage of NFC over
Bluetooth is the shorter set-up time.
• Due to its shorter range, NFC provides a
higher degree of security than Bluetooth and
makes NFC suitable for crowded areas.
• NFC can also work when one of the devices is
not powered by a battery.
• Unlike Bluetooth, no pairing code is needed.

28. Applications…
• NFC chips or tags are very small in size, it can
be embedded in the movie posters, real estate
agent posters etc.
• Health care department.
• NFC will replace car keys, ID badges and
credit/debit cards.
• Implementation in food packaging, flyers and
merchandisers as well.

29. What is Wi-Fi?
 Wi-Fi or wireless fidelity, allows you to access the internet
while on the move; you can remain online while moving
from one area to another in a wireless mode.
 Wi-Fi enabled computers send and receive data indoors
and out ;anywhere within the range of a base station.
 Its just as fast as cable modem connection.
 Wi-Fi is a generic term that refers to the IEEE 80211
communications standard for wireless local area
networks(WLANs)

33. Lifi? (light fidelity)
lifi is transmission of data through illumination
by taking the fiber out of fiber optics by
sending data through LED light bulb.
This varies in intensity faster than human eye
can follow.
It is the fast and cheap wireless
communication system which is optical
version of Wi-Fi.

34. Applications
• In vehicles and traffic lights.
• In aircrafts and underwater.
• Hospitals
• Street lamps
• Petroleum and Chemical industries

35. Advantages of wireless communication
• Wireless
• Speed
• Cost
• Durability
• Flexibility
• Place of device

36. Disadvantages of wireless
communication
• Power consumption
• Security issues
• Compatibility issues