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1. Wireless Communications

2.  What is wireless communication?
 Why we need Wireless Communications
 History and Era
 Examples
 Types of Cellular Networks
 Challenges, Advantages and Features.
 Basic Elements of Wireless Communication System
 Different types of Wireless Communication Systems
 Short-Range Wireless Communications.

Contents

3. What is wireless communication?
• In layman language it is communication in which information is
transferred between two or more points without any wire.
Wireless communications is the transmission of voice and data without
cable or wires.
 In place of a physical connection, data travels through electromagnetic
signals broadcast from sending facilities to intermediate and end-user
devices.
Definition:

4. Why we need Wireless Communications:
 The main advantage of wireless communication is mobility.
 This kind of communication provides flexibility and very easy to use
excepting mobility.
 Its infrastructure because, for the wired communication systems, the
fitting of infrastructure is a costly & time taking task whereas the
installation of wireless communication infrastructure is very simple and
less cost.

5.  Finally, we can conclude that in remote areas as well as emergency
situations, the wired communication setup is not easy but wireless
communication is a possible choice.
 There are many reasons to employ wireless communication like liberty
from wires, global coverage, flexibility & stay connected.
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6.  The first wireless transmitters went on the air in the early 20th century
using radiotelegraphy, which is radio communication using Morse code or
other coded signals.
 Later, as modulation made it possible to transmit voice and music
wirelessly, the medium became known as radio.
 Wireless transmitters use electromagnetic waves to carry voice, data,
video or signals over a communication path.
History

7.  The groundwork for modern wireless networking was laid in the early
1970s with the launch of ALOHAnet in Hawaii.
 The network, technically a wide area network (WAN), relied on ultra-high
frequency signals to broadcast data among the islands.
 The technology underpinning ALOHAnet helped fuel the creation of
Ethernet in 1973 and played an important role in the development of 802.11,
the first wireless standard.
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8. The first telegraph was invented (1600 – 1833).
The invention of the radio from the telegraph (1867-1896).
The birth of radio (1897 – 898).
Transoceanic Communication (1901 –1909).
Voice over Radio and the First Television Transmissions (1914 – 1940).
Commercial Television and the Birth of Mobile Telephony (1946 – 1976).
Cellular Mobile Telephony and Steps toward Wireless Internet (1979 – 1994)
The Wireless Data Era (1997 – 2009).
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11.  Cellular phones
 Cordless telephones
 Global positioning systems
 Cordless computer peripherals
 Wireless LANs (WLANs)
 Wireless routers
 Laptops and tablets are Wi-Fi-enabled
 Infrared (IR)
Examples of Wireless Devices

13. Types of Cellular Networks:
 For much of the 1990s and 2000s, cellular networks were supported by
two standards:
Global system for mobile communications (GSM) and
 Code Division Multiple Access (CDMA).
 GSM and CDMA each had its own access methodologies that applied
to 2G and 3G cellular specifications.
 With the advent of 4G/LTE and especially 5G, the distinctions between
the two technologies have diminished and carriers are in the process of
retiring their older GSM and CDMA networks.

14. 2G.: This first major wave of cellular technology adoption was introduced
in 1991, with speeds limited to 236.8 Kbps.
3G.: Third-generation networks began to appear in 2001. 3G offered
increased bandwidth and signal quality over 2G and provided a peak speed
of 384 kbps to 7.2 Mbps.
4G/LTE.: Fourth-generation wireless and LTE began to appear in 2009 as
successors to 3G. As opposed to the 2G and 3G standards, the
International Telecommunication Union specified a strict minimum data
rate for 4G. To be considered 4G/LTE, the cellular networks have to
transmit and receive at 100 Mbps.
…Continues

15. 5G.: Fifth-generation wireless was first introduced as a technical standard in 2016,
and carriers began to deploy it in 2019. 5G provides more bandwidth than its
predecessors, data speeds that can range as high as 20 GBPS and ultra-low latency
-- five milliseconds or less.
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16. Challenges:

17.  The transmitted distance can be anywhere between a few meters (for
example, a television's remote control) and thousands of kilometers (for
example, radio communication).
 Wireless communication can be used for cellular telephony, wireless
access to the internet, wireless home networking, and so on.
 Other applications of radio wireless technology include GPS units,
wireless computer mice, keyboards and headsets, headphones, radio
receivers, satellite television, broadcast television.
Features:

18. …Continues

19. Advantages:
 Wireless communication involves transfer of information without any
physical connection between two or more points.
 Because of this absence of any 'physical infrastructure', wireless
communication has certain advantages.
 This would often include collapsing distance or space.

20. …Continues
 Cost effectiveness
 Flexibility
 Convenience
 Reliability
 Speed
 Accessibility
 Constant connectivity etc.,

21. Disadvantages:
 Even though wireless communication has a number of advantages over
wired communication, there are a few disadvantages as well.
 The most concerning disadvantages are Interference, Security and
Health concerns etc.,

22. Basic Elements of Wireless Communication System:
 A typical Wireless Communication System can be divided into three
elements: the Transmitter, the Channel and the Receiver.

23. …Continues

24. …Continues
The Transmission Path
 It consists of Encoder, Encryption, Modulation and Multiplexing.
 The signal from the source is passed through a Source Encoder, which
converts the signal in to a suitable form for applying signal processing
techniques.
 The redundant information from signal is removed in this process in order
to maximize the utilization of resources.

25. …Continues
The Channel:
 The channel in Wireless Communication indicates the medium of
transmission of the signal i.e. open space.
 A wireless channel is unpredictable and also highly variable and
random in nature. A channel maybe subject to interference, distortion,
noise, scattering etc. and the result is that the received signal may be
filled with errors.

26. The Reception Path
 The Receiver is to collect the signal from the channel and reproduce
it as the source signal. The reception path of a Wireless
Communication System comprises of Demultiplexing, Demodulation,
Channel Decoding, Decryption and Source Decoding.
 From the components of the reception path it is clear that the task of
the receiver is just the inverse to that of transmitter.
…Continues

27. Different Types of Wireless Communication
 It takes complex technology to maintain remote wireless communication
and control of these satellites.
 In truth, wireless communication technology has an unseen impact on all
of our lives each day.
 Learn the answer by reading our in-depth guide to wireless technologies.

28. …Continues
 Satellite Communications
 Infrared Communications
 Broadcast Radio
 Micro-wave Communications
 Wi – Fi
 Mobile Communications
 Bluetooth

29.  Short-range wireless communications systems characterize a wide
range of scenarios, technologies, and requirements.
 We define short-range communications as the systems providing
wireless connectivity within a local sphere of interaction.
 Short-range wireless communication is of the following types:
 Bluetooth
 Wi-Fi
 ZigBee
 UWB
 IR
Short – Range Wireless Communications

31. Bluetooth:
 Bluetooth is a wireless communication technology standard used for
exchanging data between fixed and mobile devices over short distances.
 It uses UHF radio waves in the industrial, scientific and medical radio
bands, from 2.402 GHz to 2.480 GHz, and building personal area
networks (PANs).

32. Bluetooth and its applications in IoT:
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 Bluetooth was developed by Ericsson in 1994 uses short-wavelength
UHF waves between 2402 and 2480 MHz.
 Widely known as the best wireless transmission technology for audio
and the ubiquitous solution for hands-free calling in automobiles.
 Bluetooth is making waves in consumer and business IoT where device-
to-device communication needs to be fast, easy, and wireless.

34.  The Internet of Things (IoT) is not constricted to purely internet-based
connectivity.
 In fact, Bluetooth Low Energy (BLE) solutions are increasing the
functionality of IoT devices more successfully than via the internet.
 This creates a more reliable framework for further connectivity.
 BLE technology will enhance and optimize the overarching operability
of smart home devices by creating faster communication speeds and
extending signal range.

35. How does it work?
Piconet:
 The Bluetooth network is called a
piconet.
If it contains one master and one slave
then its called a single piconet.
 The Master is the one that initiates the communication with other devices
and it dictates when a slave device may transmit.
 Direct Slave to Slave communication is not possible.
 Maximum 8 devices including the master can communicate at any one time
in a piconet.

36. Scatternet
 Its a Combination of multiple piconets.
 Here Master of one piconet can be a slave in
another piconet. This node can receive a message
from a master in one piconet and deliver the
message to its slave into the other piconet.
 Therefore, this type of node is referred to as a bridge node. Above all, a station cannot be
master in two piconets.

38. Bluetooth Protocol Types

41. Wi-Fi (Wireless Fidelity)
 Wi-Fi is a family of wireless network protocols, based on the IEEE
802.11 family of standards.
 Devices that can use Wi-Fi technologies include personal
computer desktops and laptops, smart phones and tablets, smart
TVs, printers, smart speakers, cars, and drones.

42. Internet: Wi-Fi provides high-speed internet to users. The speed depends
on the quality of the cables.
Video conferencing: It makes video conferencing less expensive than
cellular data with excellent quality.
Common access points: In universities or colleges, it provides a single
point of the internet from where everyone can use the Wi-Fi with their
provided credentials. If you have an ethernet-only device, then you can
also connect it to your Wi-Fi. Read this article to explore more.

43. Internet and Wi – Fi:

44. Video Conferencing:

45. Common Access Points:

46. ZigBee
 Zigbee is an IEEE 802.15.4-based specification for a suite of high-level
communication protocols.
 It is used to create PANs with small, low-power digital radios, such as
for home automation and medical device data collection.
 Zigbee is a low-power, low data rate, and close proximity (i.e., personal
area) wireless network.
 Zigbee is intended to be simpler and less expensive than other wireless
PANs (WPANs), such as Bluetooth or Wi-Fi.

47. ZigBee for Internet of Things:

48. ZigBee Protocol working Examples:

49. UWB (Ultra wide band)
 Ultra-wideband (also known as UWB) is a radio technology that can use
a very low energy level for short-range, high-bandwidth communications
over a large portion of the radio spectrum.
 UWB has traditional applications in non-cooperative radar imaging.
 Recent applications target sensor data collection, precision locating, and
tracking applications.

51. IR (Infrared)
 These devices usually conform to standards published by IrDA, the
Infrared Data Association.
 Remote controls and IrDA devices use infrared light-emitting
diodes (LEDs) to emit infrared radiation that is focused by a
plastic lens into a narrow beam.
 The beam is modulated, i.e. switched on and off, to prevent interference
from other sources of infrared (like sunlight or artificial lighting).

52.  The receiver uses a silicon photo-diode to convert the infrared radiation
to an electric current.
 It responds only to the rapidly pulsing signal created by the transmitter,
and filters out slowly changing infrared radiation from ambient light.
 Infrared communications are useful for indoor use in areas of high
population density.
 Infrared is the most common way for remote controls to command
appliances.
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54. Bluetooth Vs. ZigBee Vs. Wi - Fi