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COMMUNICATION

SYSTEMS

DISCLAIMER

This presentation is meant for educational purposes only. It is based

on the book: Principles of Electronic Communication Systems,

3rdEd. 2007, by Louis E. Frenzel, Jr. McGraw-Hill.


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LESSON 1

Introduction to CommunicationSystems


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Summary in Lesson 1

1-1: What is communication?

1-2: Communication Systems

1-3: Types of Electronic Communication

1-4: Modulation and Multiplexing

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Summary in Lesson 1

(continued) 1-5: The Electromagnetic Spectrum

1-6: Bandwidth

1-7: A Survey of Communication Applications

1-8: Jobs and Careers in the Communication Industry

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1-1: What is communication?

Process of exchanging information.

Messages vs. Information vs. Data vs. Metadata

(Electronic) Communication Systems:accumulation, packaging, and exchange ofinformation.

Telecommunication systems.

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1-2: History of Telecommunications (I)

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Source: Wiki edia

Visual, auditory and ancillary methods (non-electrical):

Prehistoric: Fires, Beacons, Smoke

signals, Communication drums, Horns

6th century BCE: Mail 5th century BCE: Pigeon post

4th century BCE: Hydraulic semaphores

ca. 490 BCE: Heliographs(shield signals)

15th century CE: Maritime flag semaphores

1672: First experimental acoustic (mechanical)

telephone

1790: Semaphore lines(optical telegraphs)

1867: Signal lamps

1877:Acoustic phonograph
http://en.wikipedia.org/wiki/Firehttp://en.wikipedia.org/wiki/Beaconhttp://en.wikipedia.org/wiki/Smoke_signalshttp://en.wikipedia.org/wiki/Smoke_signalshttp://en.wikipedia.org/wiki/Drum_(communication)http://en.wikipedia.org/wiki/Horn_(acoustic)http://en.wikipedia.org/wiki/Common_Erahttp://en.wikipedia.org/wiki/Mailhttp://en.wikipedia.org/wiki/Pigeon_posthttp://en.wikipedia.org/wiki/Hydraulic_telegraphhttp://en.wikipedia.org/wiki/Heliographhttp://en.wikipedia.org/wiki/Common_Erahttp://en.wikipedia.org/wiki/Maritime_flaghttp://en.wikipedia.org/wiki/History_of_the_telephonehttp://en.wikipedia.org/wiki/History_of_the_telephonehttp://en.wikipedia.org/wiki/Semaphore_linehttp://en.wikipedia.org/wiki/Signal_lamphttp://en.wikipedia.org/wiki/Phonographhttp://en.wikipedia.org/wiki/Phonographhttp://en.wikipedia.org/wiki/Phonographhttp://en.wikipedia.org/wiki/Phonographhttp://en.wikipedia.org/wiki/Signal_lamphttp://en.wikipedia.org/wiki/Signal_lamphttp://en.wikipedia.org/wiki/Signal_lamphttp://en.wikipedia.org/wiki/Semaphore_linehttp://en.wikipedia.org/wiki/Semaphore_linehttp://en.wikipedia.org/wiki/Semaphore_linehttp://en.wikipedia.org/wiki/History_of_the_telephonehttp://en.wikipedia.org/wiki/History_of_the_telephonehttp://en.wikipedia.org/wiki/History_of_the_telephonehttp://en.wikipedia.org/wiki/History_of_the_telephonehttp://en.wikipedia.org/wiki/History_of_the_telephonehttp://en.wikipedia.org/wiki/History_of_the_telephonehttp://en.wikipedia.org/wiki/History_of_the_telephonehttp://en.wikipedia.org/wiki/History_of_the_telephonehttp://en.wikipedia.org/wiki/History_of_the_telephonehttp://en.wikipedia.org/wiki/Maritime_flaghttp://en.wikipedia.org/wiki/Maritime_flaghttp://en.wikipedia.org/wiki/Maritime_flaghttp://en.wikipedia.org/wiki/Maritime_flaghttp://en.wikipedia.org/wiki/Maritime_flaghttp://en.wikipedia.org/wiki/Common_Erahttp://en.wikipedia.org/wiki/Heliographhttp://en.wikipedia.org/wiki/Hydraulic_telegraphhttp://en.wikipedia.org/wiki/Hydraulic_telegraphhttp://en.wikipedia.org/wiki/Hydraulic_telegraphhttp://en.wikipedia.org/wiki/Pigeon_posthttp://en.wikipedia.org/wiki/Pigeon_posthttp://en.wikipedia.org/wiki/Pigeon_posthttp://en.wikipedia.org/wiki/Mailhttp://en.wikipedia.org/wiki/Common_Erahttp://en.wikipedia.org/wiki/Horn_(acoustic)http://en.wikipedia.org/wiki/Drum_(communication)http://en.wikipedia.org/wiki/Drum_(communication)http://en.wikipedia.org/wiki/Drum_(communication)http://en.wikipedia.org/wiki/Smoke_signalshttp://en.wikipedia.org/wiki/Smoke_signalshttp://en.wikipedia.org/wiki/Smoke_signalshttp://en.wikipedia.org/wiki/Beaconhttp://en.wikipedia.org/wiki/Fire


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1-2: History of Telecommunications (II)

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Source: Wiki edia

Basic electrical signals:

1838: Electrical telegraph.

1858: First trans-Atlantic telegraph cable 1876: Telephone.

1880: Telephony via lightbeam photophones
http://en.wikipedia.org/wiki/Electrical_telegraphhttp://en.wikipedia.org/wiki/Transatlantic_telegraph_cablehttp://en.wikipedia.org/wiki/Telephonehttp://en.wikipedia.org/wiki/Photophonehttp://en.wikipedia.org/wiki/Photophonehttp://en.wikipedia.org/wiki/Photophonehttp://en.wikipedia.org/wiki/Photophonehttp://en.wikipedia.org/wiki/Photophonehttp://en.wikipedia.org/wiki/Telephonehttp://en.wikipedia.org/wiki/Transatlantic_telegraph_cablehttp://en.wikipedia.org/wiki/Transatlantic_telegraph_cablehttp://en.wikipedia.org/wiki/Transatlantic_telegraph_cablehttp://en.wikipedia.org/wiki/Electrical_telegraph


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1-2: History of Telecommunications (III)

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Source: Wiki edia

Advanced electrical and electronic signals:

1893: Wireless telegraphy

1896: Radio.

1914: First North American transcontinental telephone calling

1927: Television.

1930: First experimental videophones

1936: World's first public videophone network 1946: Limited capacity Mobile Telephone Service for automobiles

1956: Transatlantic telephone cable

1962: Commercial telecommunications satellite

1964: Fiber optical telecommunications

1965: First North American public videophone network

1969: Computer networking

1973: First modern-era mobile (cellular) phone

1979: INMARSAT ship-to-shore satellite communications

1981: First mobile (cellular) phone network

1982: SMTP email

1983: Internet.

1998: Mobile satellite hand-held phones

2003: VoIP Internet Telephony 2007: iPhone (1st generation)
http://en.wikipedia.org/wiki/Radio_telegraphhttp://en.wikipedia.org/wiki/Radiohttp://en.wikipedia.org/wiki/Long_distance_callinghttp://en.wikipedia.org/wiki/Televisionhttp://en.wikipedia.org/wiki/Videophonehttp://en.wikipedia.org/wiki/Videophonehttp://en.wikipedia.org/wiki/Mobile_Telephone_Servicehttp://en.wikipedia.org/wiki/Transatlantic_communications_cablehttp://en.wikipedia.org/wiki/Telstarhttp://en.wikipedia.org/wiki/Optical_fiberhttp://en.wikipedia.org/wiki/Videophonehttp://en.wikipedia.org/wiki/Computer_networkinghttp://en.wikipedia.org/wiki/Mobile_phonehttp://en.wikipedia.org/wiki/International_Mobile_Satellite_Organizationhttp://en.wikipedia.org/wiki/Mobile_phonehttp://en.wikipedia.org/wiki/Simple_Mail_Transfer_Protocolhttp://en.wikipedia.org/wiki/Internethttp://en.wikipedia.org/wiki/Satellite_phonehttp://en.wikipedia.org/wiki/VoIPhttp://en.wikipedia.org/wiki/IPhone_(1st_generation)http://en.wikipedia.org/wiki/IPhone_(1st_generation)http://en.wikipedia.org/wiki/IPhone_(1st_generation)http://en.wikipedia.org/wiki/IPhone_(1st_generation)http://en.wikipedia.org/wiki/VoIPhttp://en.wikipedia.org/wiki/VoIPhttp://en.wikipedia.org/wiki/VoIPhttp://en.wikipedia.org/wiki/VoIPhttp://en.wikipedia.org/wiki/Satellite_phonehttp://en.wikipedia.org/wiki/Satellite_phonehttp://en.wikipedia.org/wiki/Satellite_phonehttp://en.wikipedia.org/wiki/Satellite_phonehttp://en.wikipedia.org/wiki/Satellite_phonehttp://en.wikipedia.org/wiki/Satellite_phonehttp://en.wikipedia.org/wiki/Satellite_phonehttp://en.wikipedia.org/wiki/Satellite_phonehttp://en.wikipedia.org/wiki/Internethttp://en.wikipedia.org/wiki/Simple_Mail_Transfer_Protocolhttp://en.wikipedia.org/wiki/Mobile_phonehttp://en.wikipedia.org/wiki/Mobile_phonehttp://en.wikipedia.org/wiki/Mobile_phonehttp://en.wikipedia.org/wiki/Mobile_phonehttp://en.wikipedia.org/wiki/Mobile_phonehttp://en.wikipedia.org/wiki/Mobile_phonehttp://en.wikipedia.org/wiki/Mobile_phonehttp://en.wikipedia.org/wiki/Mobile_phonehttp://en.wikipedia.org/wiki/Mobile_phonehttp://en.wikipedia.org/wiki/Mobile_phonehttp://en.wikipedia.org/wiki/International_Mobile_Satellite_Organizationhttp://en.wikipedia.org/wiki/International_Mobile_Satellite_Organizationhttp://en.wikipedia.org/wiki/International_Mobile_Satellite_Organizationhttp://en.wikipedia.org/wiki/International_Mobile_Satellite_Organizationhttp://en.wikipedia.org/wiki/International_Mobile_Satellite_Organizationhttp://en.wikipedia.org/wiki/International_Mobile_Satellite_Organizationhttp://en.wikipedia.org/wiki/International_Mobile_Satellite_Organizationhttp://en.wikipedia.org/wiki/International_Mobile_Satellite_Organizationhttp://en.wikipedia.org/wiki/International_Mobile_Satellite_Organizationhttp://en.wikipedia.org/wiki/Mobile_phonehttp://en.wikipedia.org/wiki/Mobile_phonehttp://en.wikipedia.org/wiki/Mobile_phonehttp://en.wikipedia.org/wiki/Mobile_phonehttp://en.wikipedia.org/wiki/Mobile_phonehttp://en.wikipedia.org/wiki/Mobile_phonehttp://en.wikipedia.org/wiki/Mobile_phonehttp://en.wikipedia.org/wiki/Mobile_phonehttp://en.wikipedia.org/wiki/Mobile_phonehttp://en.wikipedia.org/wiki/Mobile_phonehttp://en.wikipedia.org/wiki/Mobile_phonehttp://en.wikipedia.org/wiki/Computer_networkinghttp://en.wikipedia.org/wiki/Computer_networkinghttp://en.wikipedia.org/wiki/Computer_networkinghttp://en.wikipedia.org/wiki/Videophonehttp://en.wikipedia.org/wiki/Videophonehttp://en.wikipedia.org/wiki/Videophonehttp://en.wikipedia.org/wiki/Videophonehttp://en.wikipedia.org/wiki/Videophonehttp://en.wikipedia.org/wiki/Videophonehttp://en.wikipedia.org/wiki/Videophonehttp://en.wikipedia.org/wiki/Videophonehttp://en.wikipedia.org/wiki/Optical_fiberhttp://en.wikipedia.org/wiki/Optical_fiberhttp://en.wikipedia.org/wiki/Optical_fiberhttp://en.wikipedia.org/wiki/Optical_fiberhttp://en.wikipedia.org/wiki/Optical_fiberhttp://en.wikipedia.org/wiki/Telstarhttp://en.wikipedia.org/wiki/Telstarhttp://en.wikipedia.org/wiki/Telstarhttp://en.wikipedia.org/wiki/Telstarhttp://en.wikipedia.org/wiki/Telstarhttp://en.wikipedia.org/wiki/Transatlantic_communications_cablehttp://en.wikipedia.org/wiki/Transatlantic_communications_cablehttp://en.wikipedia.org/wiki/Transatlantic_communications_cablehttp://en.wikipedia.org/wiki/Transatlantic_communications_cablehttp://en.wikipedia.org/wiki/Transatlantic_communications_cablehttp://en.wikipedia.org/wiki/Mobile_Telephone_Servicehttp://en.wikipedia.org/wiki/Mobile_Telephone_Servicehttp://en.wikipedia.org/wiki/Mobile_Telephone_Servicehttp://en.wikipedia.org/wiki/Mobile_Telephone_Servicehttp://en.wikipedia.org/wiki/Mobile_Telephone_Servicehttp://en.wikipedia.org/wiki/Mobile_Telephone_Servicehttp://en.wikipedia.org/wiki/Mobile_Telephone_Servicehttp://en.wikipedia.org/wiki/Mobile_Telephone_Servicehttp://en.wikipedia.org/wiki/Mobile_Telephone_Servicehttp://en.wikipedia.org/wiki/Mobile_Telephone_Servicehttp://en.wikipedia.org/wiki/Mobile_Telephone_Servicehttp://en.wikipedia.org/wiki/Mobile_Telephone_Servicehttp://en.wikipedia.org/wiki/Videophonehttp://en.wikipedia.org/wiki/Videophonehttp://en.wikipedia.org/wiki/Videophonehttp://en.wikipedia.org/wiki/Videophonehttp://en.wikipedia.org/wiki/Videophonehttp://en.wikipedia.org/wiki/Videophonehttp://en.wikipedia.org/wiki/Videophonehttp://en.wikipedia.org/wiki/Videophonehttp://en.wikipedia.org/wiki/Videophonehttp://en.wikipedia.org/wiki/Videophonehttp://en.wikipedia.org/wiki/Videophonehttp://en.wikipedia.org/wiki/Videophonehttp://en.wikipedia.org/wiki/Videophonehttp://en.wikipedia.org/wiki/Televisionhttp://en.wikipedia.org/wiki/Long_distance_callinghttp://en.wikipedia.org/wiki/Long_distance_callinghttp://en.wikipedia.org/wiki/Long_distance_callinghttp://en.wikipedia.org/wiki/Long_distance_callinghttp://en.wikipedia.org/wiki/Long_distance_callinghttp://en.wikipedia.org/wiki/Long_distance_callinghttp://en.wikipedia.org/wiki/Radiohttp://en.wikipedia.org/wiki/Radio_telegraphhttp://en.wikipedia.org/wiki/Radio_telegraphhttp://en.wikipedia.org/wiki/Radio_telegraph


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1-2: History of Telecommunications (IV)

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Source: Wiki edia


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Analog Signals An analog signalis a smoothly and continuously varying voltage

or current. Examples are:

Sine wave

Voice Video (TV)

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Figure 1-5: Analog signals (a) Sine wave tone. (b) Voice. (c) Video (TV) signal.Source: [Frenzel, 2007]


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Digital Signals Digital signals change in steps or in discrete increments.

Most digital signals use binary or two-state codes. Examples are:

Telegraph (Morse code)

Continuous wave (CW) code

Serial binary code (used in computers)

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Figure 1-6: Digital signals (a) Telegraph (Morse code). (b) Continuous-wave (CW)

code. (c) Serial binary code.Source: [Frenzel, 2007]


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Digital Signals

Many transmissions are of signals that originate in digital form but

must be converted to analog form to match the transmission

medium.

Digital data over the telephone network. Analog signals.

They are first digitized with an analog-to-digital (A/D)

converter.

The data can then be transmitted and processed by

computers and other digital circuits.

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Analog vs Digital

Basic components: Transmitter (signal processing, carrier circuits)

Channel or medium

Receiver (carrier circuits, signal processing)

Noisedegrades or interferes with transmittedinformation.

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Source: [Frenzel, 2007]

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Transmitter

The transmitter is a collection of electronic components and

circuits that converts the electrical signal into a signal suitable for

transmission over a given medium.

Transmitters are made up of oscillators, amplifiers, tuned circuits

and filters, modulators, frequency mixers, frequency synthesizers,

and other circuits.

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Communication Channel The communication channelis the medium by which the

electronic signal is sent from one place to another.

Types of media include:

Wired:

Electrical conductors

Optical media

Wireless:

Free space

System-specific media (e.g., water is the medium for sonar).

Attenuation. Bandwidth.

Noiseis random, undesirable energy that enters thecommunication system via the communicating medium anddegrades or interferes with the transmitted message.

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Receivers

A receiveris a collection of electronic components and circuits that

accepts the transmitted message from the channel and converts it

back into a form understandable by humans.

Receivers contain amplifiers, oscillators, mixers, tuned circuits andfilters, and a demodulator or detector that recovers the original

intelligence signal from the modulated carrier.

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Transceivers A transceiveris an electronic unit that incorporates circuits that

both send and receive signals.

Examples are:

Telephones

Fax machines

Handheld CB radios

Cell phones

Computer modems

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1-4: Types of Communication Systems

Channel

Wired

Wireless

Bandwidth

Narrowband

Wideband (Spread spectrum)

Number of sources/targets

One-to-One (Unicast, Anycast)

One-to-Many (Broadcast, Multicast)

Many-to-One

Many-to-Many

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Baseband Transmission Basebandinformation can be sent directly and unmodified over

the medium or can be used to modulate a carrier for transmissionover the medium.

In telephone or intercom systems, the voice is placed onthe wires and transmitted.

In some computer networks, the digital signals areapplied directly to coaxial or twisted-pair cables fortransmission.

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Broadband Transmission A carrieris a high frequency signal that is modulated by audio,

video, or data.

A radio-frequency (RF) waveis an electromagnetic signal that isable to travel long distances through space.

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Broadband Transmission A broadband transmission takes place when a carrier signal is

modulated, amplified, and sent to the antenna for transmission.

The two most common methods of modulation are:

Amplitude Modulation (AM) Frequency Modulation (FM)

Another method is called phase modulation (PM),in which the

phase angle of the sine wave is varied.

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Broadband Transmission Frequency-shift keying (FSK)takes place when data is converted

to frequency-varying tones.

Devices called modems(modulator-demodulator) translate thedata from digital to analog and back again.

Demodulationor detection takes place in the receiver when theoriginal baseband (e.g. audio) signal is extracted.

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1-5-1: Modulation

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Figure 1-7: Modulation at the transmitter. Source: [Frenzel, 2007]

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1-5-1: Modulation

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Figure 1-8: Types of modulation. (a) Amplitude modulation. (b) Frequency modulation.Source: [Frenzel, 2007]


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1-5-2: Multiplexing

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Figure 1-11: Multiplexing at the transmitter. Source: [Frenzel, 2007]

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1-5-3: Multiaccess

Multiaccess

Multiaccess is the process of allowing two or more signals from

different sources to share the same medium or channel.

The four basic types of multiaccess mechanism are:

Space division Frequency division

Time division

Code division

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1-6: The Electromagnetic Spectrum

The range of electromagnetic signals encompassing all

frequencies is referred to as the electromagnetic

spectrum.

It is a limited natural resource.

Spectrum management is provided by agencies set up

by each country to control spectrum use.

Standardsare specifications and guidelines necessary

to ensure compatibility between transmitting and

receiving equipment.

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International regulatory body (193 members) [Wikipedia]:

International Telecommunication Union

Radiocommunication (ITU-R)

Managing the international radio-frequency spectrum and satellite orbit

resources is at the heart of the work of the ITU Radiocommunication Sector

(ITU-R).

Standardization (ITU-T)

ITU's standards-making efforts are its best-knownand oldestactivity;

known prior to 1992 as the International Telephone and Telegraph

Consultative Committee or CCITT(from its French name "Comit consultatif

international tlphonique et tlgraphique")

Development (ITU-D)

Established to help spread equitable, sustainable and affordable access to

information and communication technologies (ICT).

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http://en.wikipedia.org/wiki/ITU-Rhttp://en.wikipedia.org/wiki/ITU-Thttp://en.wikipedia.org/wiki/ITU-Dhttp://en.wikipedia.org/wiki/ITU-Dhttp://en.wikipedia.org/wiki/ITU-Dhttp://en.wikipedia.org/wiki/ITU-Dhttp://en.wikipedia.org/wiki/ITU-Thttp://en.wikipedia.org/wiki/ITU-Thttp://en.wikipedia.org/wiki/ITU-Thttp://en.wikipedia.org/wiki/ITU-Rhttp://en.wikipedia.org/wiki/ITU-Rhttp://en.wikipedia.org/wiki/ITU-R


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Other telecommunications regulatory bodies:

Federal Communications Commission (FCC) - USA

Die Bundesnetzagentur fr Elektrizitt, Gas, Telekommunikation,

Post und Eisenbahnen (BundesnetzagenturBNetzA)Germany

Electronic Communications Committee (ECC) as a component ofthe European Conference of Postal and Telecommunications

Administrations (CEPT)

Communications Regulatory Comission (CRC), MinTIC - Colombia

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Figure 1-13: The electromagnetic spectrum. Source: [Frenzel, 2007]


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Figure 1-15: Frequency and wavelength. (a) One cycle. (b) One wavelength.Source: [Frenzel, 2007]

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Example:

What is the wavelength if the frequency is 4MHz?

Frequency and Wavelength: Wavelength

Wavelength () = speed of light frequency

Speed of light = 3 108meters/second

Therefore:= 3 108/ f

= 3 108/ 4 MHz

= 75 meters (m)


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1-6-1: The Radio Spectrum

Frequency Ranges from 30 Hz to 300 GHz

The radio spectrum is a part of the electromagnetic spectrum and it is

divided into segments:

Extremely Low Frequencies (ELF) 30300 Hz.

Voice Frequencies (VF) 3003000 Hz.

Very Low Frequencies (VLF) include the higher end of the

human hearing range up to

about 20 kHz.

Low Frequencies (LF) 30300 kHz.

Medium Frequencies (MF) 3003000 kHz

AM radio 5351605 kHz.


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Frequency Ranges from 30 Hz to 300 GHzHigh Frequencies (HF)

(short waves; VOA, BBC

broadcasts; government andmilitary two-way communication;

amateur radio, CB.

330 MHz

Very High Frequencies (VHF)

FM radio broadcasting (88108

MHz), television channels 213.

30300 MHz

Ultra High Frequencies (UHF)

TV channels 1467, cellular

phones, military communication.

3003000 MHz


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Frequency Ranges from 30 Hz to 300 GHz

Microwaves and Super High

Frequencies (SHF)

Satellite communication, radar,wireless LANs, microwave ovens

130 GHz

Extremely High Frequencies (EHF)

Satellite communication, computer

data, radar

30300 GHz

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1-6-2: The Optical Spectrum

Optical Spectrum

The optical spectrumexists directly above the millimeter wave

region.

Three types of light waves are:

Infrared Visible spectrum

Ultraviolet

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Optical Spectrum: Infrared Infrared radiation is produced by any physical equipment that

generates heat, including our bodies.

Infrared is used:

In astronomy, to detect stars and other physical bodies in theuniverse,

For guidance in weapons systems, where the heat radiatedfrom airplanes or missiles can be detected and used to guidemissiles to targets.

In most new TV remote-control units, where special codedsignals are transmitted by an infrared LED to the TV receiverto change channels, set the volume, and perform otherfunctions.

In some of the newer wireless LANs and all fiber-opticcommunication.

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Optical Spectrum: The Visible Spectrum

Just above the infrared region is the visible spectrumwe refer to

as light.

Red is low-frequency or long-wavelength light

Violet is high-frequency or short-wavelength light. Light waves very high frequency enables them to handle a

tremendous amount of information (the bandwidth of the baseband

signals can be very wide).

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1-6: The Optical Spectrum

Optical Spectrum: Ultraviolet

Ultraviolet is not used for communication

Its primary use is medical.

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1-6-3: Bandwidth

Bandwidth (BW)is that portion of the electromagneticspectrum occupied by a signal.

Channel bandwidthrefers to the range of frequenciesrequired to transmit the desired information.

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1-6-3: Bandwidth

More Room at the Top

Today, virtually the entire frequency spectrum between

approximately 30 kHz and 300 MHz has been spoken for.

There is tremendous competition for these frequencies, between

companies, individuals, and government services in individualcarriers and between the different nations of the world.

The electromagnetic spectrum is one of our most precious natural

resources.

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1-6-3: Bandwidth

More Room at the Top

Communication engineering is devoted to making the best use of

that finite spectrum.

Great effort goes into developing communication techniques that

minimize the bandwidth required to transmit given information andthus conserve spectrum space.

This provides more room for additional communication channels

and gives other services or users an opportunity to take advantage

of it.

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1-7: A Survey of

Communications Applications

Simplex

AM and FMbroadcasting

Digital radio

TV broadcasting

Digital television(DTV)

Cable television

Facsimile

Wireless remotecontrol

Paging services

Navigation and

direction-findingservices

Telemetry

Radio astronomy

Surveillance Music services

Internet radio andvideo

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1-7: A Survey of

Communications Applications Duplex

Telephones

Two-way radio

Radar

Sonar Amateur radio

Citizens radio

Family Radio service

The Internet

Wide-area networks

(WANs)

Metropolitan-area

networks (MANs)

Local area networks(LANs)

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1-8: Jobs and Careers in the

Communication Industry The electronics industry is roughly divided into

four major specializations:1. Communications (largest in terms of people

employed and the dollar value of equipment

purchased)2. Computers (second largest).

3. Industrial controls.

4. Instrumentation.

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Communication IndustryTypes of Jobs

Engineers design communication equipment and systems.

Technicians install, troubleshoot, repair, calibrate, and maintain

equipment.

Engineering Technicians assist in equipment design, testing, and

assembly.

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Communication IndustryTypes of Jobs

Technical sales representatives determine customer needs andrelated specifications, write proposals and sell equipment.

Technical writers generate technical documentation for equipment

and systems.

Trainers develop programs, generate training and presentationmaterials, and conduct classroom training.


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Communication Industry

Figure 1-18:Structure of the communication electronics industry.Source: [Frenzel, 2007]

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References

[Frenzel, 2007] Frenzel, Louis E. Principles of Electronic

Communication Systems, 3rdEd. McGraw-Hill, 2007.

[Wikipedia] Wikipedia in English, the free Encyclopedia.

Visited on Nov. 2013.

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