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CSC 4315
(WIRELESS NETWORKS AND
PROTOCOLS)
LECTURE 2
Department of Maths and Computer-
Science
Faculty of Natural and Applied Science
BY
DR. BABANGIDA ALBABA
AND
UMAR DANJUMA MAIWADA
RADIO SPECTRUM
 The radio spectrum is the part of the
electromagnetic spectrum with frequencies from
30 Hertz to 300 GHz. Electromagnetic waves in this
frequency range, called radio waves, are extremely
widely used in modern technology, particularly in
telecommunication. To prevent interference
between different users
2
RADIO SPECTRUM RANGE
 Radio spectrum refers to part of the EM spectrum in
the frequency range from 3 kHz to 300 GHz that is
specifically used for wireless communication.
 The radio spectrum is the home of communication
technologies such as mobile phones, radio and
television broadcasting, two-way radios, broadband
services, radar, fixed links, satellite
communications, etc. due to its excellent ability to
carry codified information (signals).
3
4
RADIO BANDS
 A radio band is a small contiguous section of the radio
spectrum frequencies, in which channels are usually used or
set aside for the same purpose. To prevent interference and
allow for efficient use of the radio spectrum, similar services
are allocated in bands. For example, broadcasting, mobile
radio, or navigation devices, will be allocated in non-
overlapping ranges of frequencies.
 The radio spectrum is divided into frequency bands and
sub-bands.
 The sub-bands are further divided into channels whose size
can vary band by band. VHF Band II, the home of FM radio,
for instance, is sliced up in 100 kHz-wide channels. An FM
station requires 300 kHz bandwidth, therefore each FM radio
station takes up three spectrum channels.
 In the case of television broadcasting, the agreed bandwidth
of a channel is 8 MHz in UHF Band IV/V. The bandwidth
5
6
BANDWIDTH OF RADIO BANDS
 Lower frequency bands have less bandwidth
capacity than higher bands. It means signals that
carry a lot of information (such as TV, broadband or
mobile phones) are better placed in the higher
frequency bands while simple radio (audio) signals
can be carried by the low frequency waves.
 Even though low frequencies travel long distances,
since they have low bandwidth they cannot be used
for TV transmission for example (which uses a lot of
bandwidth) because that would mean that most of
the Long Wave and Medium Wave radio services
would be squeezed out. 7
8
PROPAGATION MODES, COVERAGE &
APPLICATIONS OF RADIO BANDS
9
APPLICATIONS OF OTHER EM WAVES
10
SHANNON’S THEOREM
 In information theory, the noisy-channel coding
theorem (sometimes Shannon's theorem or
Shannon's limit), establishes that for any given
degree of noise contamination of a communication
channel, it is possible to communicate discrete data
(digital information) nearly error-free up to a
computable maximum rate through the channel.
 The theorem describes the maximum possible
efficiency of error-correcting methods versus levels
of noise interference and data corruption.
Shannon's theorem has wide-ranging applications
in both communications and data storage. 11
- SHANNON'S THEOREM GIVES AN UPPER BOUND TO THE CAPACITY (TRANSMISSION
SPEED) OF A TRANSMISSION CHANNEL, IN BITS PER SECOND (BPS), AS A FUNCTION OF
THE AVAILABLE BANDWIDTH AND SIGNAL-TO-NOISE RATIO (S/N) OF THE CHANNEL.
- THE THEOREM CAN BE STATED AS C = B*LOG2(1 + S/N), WHERE
O C = MAXIMUM CHANNEL CAPACITY (BPS),
O B = BANDWIDTH OF THE LINK (HZ),
O S = AVERAGE SIGNAL POWER
O N = AVERAGE NOISE POWER
- NOISE IS A SUMMATION OF UNWANTED OR DISTURBING ENERGY (FROM NATURAL OR MAN-
MADE SOURCES) THAT INTERFERES WITH THE TRANSMISSION OF A COMMUNICATION
SIGNAL. IN TELEPHONE CONVERSATIONS, NOISE MIGHT BE CAUSED BY STATIC IN THE LINE,
CROSS TALK FROM ANOTHER LINE, OR BACKGROUND SOUNDS.
- THERMAL NOISE IS UNAVOIDABLE AT NON-ZERO TEMPERATURE, WHILE OTHER TYPES
DEPEND MOSTLY ON DEVICE TYPE OR MANUFACTURING QUALITY AND SEMICONDUCTOR
DEFECTS, SUCH AS CONDUCTANCE FLUCTUATIONS.
12
LICENSED RADIO SPECTRUM
 Spectrum management is the process of regulating the use
of radio frequencies to promote efficient and effective use.
Because two or more radio signals using the same frequency
can often interfere with one another, government regulators
and international agencies have reserved certain
frequencies for which they issue exclusive licenses to
individual users.
 The range of frequencies within the EM spectrum that are
reserved make up the Licensed Spectrum. Individual
companies pay a licensing fee for the exclusive right to
transmit on assigned channels within that band in a given
geographic area.
 At the international level, the International
Telecommunication Union (ITU) and regional bodies e.g.
West Africa Telecommunications Regulators Assembly
(WATRA) are deeply involved in agreeing and assigning
future spectrum bands for mobile, bound by international
treaty.
13
UNLICENSED RADIO SPECTRUM
 Without spectrum licensing, interference would
garble multiple transmitters signals, preventing
decent reception. However, licensing would be very
impractical for certain uses, like communication
between your cordless handset and base unit, or
interaction between your wireless keyboard and
PC, or WiFi networks. Instead, these wireless
technologies transmit in Unlicensed Spectrum
(also called the ISM band).
 Unlicensed band transmissions don't require any
permission, so long as products and users comply
with the rules e.g. maximum transmission power.
Thus unlicensed wireless technologies are
vulnerable to interference. This is why your home or
business WLAN can experience signal corruption
14
15
QUESTIONS
THANK YOU FOR YOUR ATTENTION !!!
16

0 lecture 2 wp wireless protocol

  • 1.
    CSC 4315 (WIRELESS NETWORKSAND PROTOCOLS) LECTURE 2 Department of Maths and Computer- Science Faculty of Natural and Applied Science BY DR. BABANGIDA ALBABA AND UMAR DANJUMA MAIWADA
  • 2.
    RADIO SPECTRUM  Theradio spectrum is the part of the electromagnetic spectrum with frequencies from 30 Hertz to 300 GHz. Electromagnetic waves in this frequency range, called radio waves, are extremely widely used in modern technology, particularly in telecommunication. To prevent interference between different users 2
  • 3.
    RADIO SPECTRUM RANGE Radio spectrum refers to part of the EM spectrum in the frequency range from 3 kHz to 300 GHz that is specifically used for wireless communication.  The radio spectrum is the home of communication technologies such as mobile phones, radio and television broadcasting, two-way radios, broadband services, radar, fixed links, satellite communications, etc. due to its excellent ability to carry codified information (signals). 3
  • 4.
  • 5.
    RADIO BANDS  Aradio band is a small contiguous section of the radio spectrum frequencies, in which channels are usually used or set aside for the same purpose. To prevent interference and allow for efficient use of the radio spectrum, similar services are allocated in bands. For example, broadcasting, mobile radio, or navigation devices, will be allocated in non- overlapping ranges of frequencies.  The radio spectrum is divided into frequency bands and sub-bands.  The sub-bands are further divided into channels whose size can vary band by band. VHF Band II, the home of FM radio, for instance, is sliced up in 100 kHz-wide channels. An FM station requires 300 kHz bandwidth, therefore each FM radio station takes up three spectrum channels.  In the case of television broadcasting, the agreed bandwidth of a channel is 8 MHz in UHF Band IV/V. The bandwidth 5
  • 6.
  • 7.
    BANDWIDTH OF RADIOBANDS  Lower frequency bands have less bandwidth capacity than higher bands. It means signals that carry a lot of information (such as TV, broadband or mobile phones) are better placed in the higher frequency bands while simple radio (audio) signals can be carried by the low frequency waves.  Even though low frequencies travel long distances, since they have low bandwidth they cannot be used for TV transmission for example (which uses a lot of bandwidth) because that would mean that most of the Long Wave and Medium Wave radio services would be squeezed out. 7
  • 8.
  • 9.
    PROPAGATION MODES, COVERAGE& APPLICATIONS OF RADIO BANDS 9
  • 10.
  • 11.
    SHANNON’S THEOREM  Ininformation theory, the noisy-channel coding theorem (sometimes Shannon's theorem or Shannon's limit), establishes that for any given degree of noise contamination of a communication channel, it is possible to communicate discrete data (digital information) nearly error-free up to a computable maximum rate through the channel.  The theorem describes the maximum possible efficiency of error-correcting methods versus levels of noise interference and data corruption. Shannon's theorem has wide-ranging applications in both communications and data storage. 11
  • 12.
    - SHANNON'S THEOREMGIVES AN UPPER BOUND TO THE CAPACITY (TRANSMISSION SPEED) OF A TRANSMISSION CHANNEL, IN BITS PER SECOND (BPS), AS A FUNCTION OF THE AVAILABLE BANDWIDTH AND SIGNAL-TO-NOISE RATIO (S/N) OF THE CHANNEL. - THE THEOREM CAN BE STATED AS C = B*LOG2(1 + S/N), WHERE O C = MAXIMUM CHANNEL CAPACITY (BPS), O B = BANDWIDTH OF THE LINK (HZ), O S = AVERAGE SIGNAL POWER O N = AVERAGE NOISE POWER - NOISE IS A SUMMATION OF UNWANTED OR DISTURBING ENERGY (FROM NATURAL OR MAN- MADE SOURCES) THAT INTERFERES WITH THE TRANSMISSION OF A COMMUNICATION SIGNAL. IN TELEPHONE CONVERSATIONS, NOISE MIGHT BE CAUSED BY STATIC IN THE LINE, CROSS TALK FROM ANOTHER LINE, OR BACKGROUND SOUNDS. - THERMAL NOISE IS UNAVOIDABLE AT NON-ZERO TEMPERATURE, WHILE OTHER TYPES DEPEND MOSTLY ON DEVICE TYPE OR MANUFACTURING QUALITY AND SEMICONDUCTOR DEFECTS, SUCH AS CONDUCTANCE FLUCTUATIONS. 12
  • 13.
    LICENSED RADIO SPECTRUM Spectrum management is the process of regulating the use of radio frequencies to promote efficient and effective use. Because two or more radio signals using the same frequency can often interfere with one another, government regulators and international agencies have reserved certain frequencies for which they issue exclusive licenses to individual users.  The range of frequencies within the EM spectrum that are reserved make up the Licensed Spectrum. Individual companies pay a licensing fee for the exclusive right to transmit on assigned channels within that band in a given geographic area.  At the international level, the International Telecommunication Union (ITU) and regional bodies e.g. West Africa Telecommunications Regulators Assembly (WATRA) are deeply involved in agreeing and assigning future spectrum bands for mobile, bound by international treaty. 13
  • 14.
    UNLICENSED RADIO SPECTRUM Without spectrum licensing, interference would garble multiple transmitters signals, preventing decent reception. However, licensing would be very impractical for certain uses, like communication between your cordless handset and base unit, or interaction between your wireless keyboard and PC, or WiFi networks. Instead, these wireless technologies transmit in Unlicensed Spectrum (also called the ISM band).  Unlicensed band transmissions don't require any permission, so long as products and users comply with the rules e.g. maximum transmission power. Thus unlicensed wireless technologies are vulnerable to interference. This is why your home or business WLAN can experience signal corruption 14
  • 15.
  • 16.
    QUESTIONS THANK YOU FORYOUR ATTENTION !!! 16