CHAPTER 5
Distribution by Wired Relays, Wireless Relays,
and over the Internet
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LEARNING OBJECTIVES
After reading this chapter students should be able to understand the following concepts:
Role of storage: Understand why programmers and electronic media executives are concerned with
recording and storing programs for later use
Terrestrial relays: Understand the need for networking, and describe the evolution of networking via
Earth-based technologies. Trace the progress from the development of coaxial cable through the use of
microwave relays to today’s advances in delivery systems using fiber optics
Satellite relays: Comprehend the relationship of satellite relays to terrestrial relays. Outline the
advantages and disadvantages of satellite relays. Understand how geostationary orbits, spectrum
allocations for satellites, satellite transmission, and signal reception work
CHAPTER FOCUS
In this chapter, the emphasis is on the functions technology serves in the delivery of audio/voice, data,
and video. If you explain the unique functions of the media using this approach, students will more
readily grasp key concepts presented here. This logical way of discussing technology helps place all
technology within a coherent framework. Again, explanatory material in the exhibits will help break
down concepts into understandable form.
How are programs relayed or distributed by electronic media delivery systems? They’re disbursed in a
number of different ways, including terrestrial relays (coaxial cable, microwave relays, and fiber-optic
TERMS, CONCEPTS, AND EXERCISES
Wire Relays
Terms: relay, bandwidth, POTS (plain old telephone service), coaxial cable, fiber-optic cable, lasers,
light-emitting diodes (LEDs), twisted copper pairs
oIntroduce differences between wire relays – fiber-optic, coaxial cable, and twisted copper pairs
(use Exhibits 5.a).
Cable and Telephone Distribution Networks
Terms: “triple play,” headend, tree-and-branch architecture, trunk cable, feeder cable, drop cable, hybrid
fiber-coaxial (HFC), optical node, fiber to the node (FTTN), FiOS network, fiber to the home (FTTH),
Internet Protocol Multicast, converter box, addressable converter boxes, set-top box (STB), cable card,
video-on-demand (VOD), digital STB
oHow does cable work? What happens at the headend? What is meant by tree-and-branch
architecture? What is a trunk? A feeder? A drop cable? (See Exhibit 5.b.)
oWhat are drawbacks to cable? How do firms try to overcome them?
oHow is fiber being used cable systems and telephone companies? Use Exhibits 5.c and 5.d to
illustrate the differences in network architecture how it affects service delivery. What are the
advantages of fiber to the home networks such as Verizon’s FiOS? Discuss the services that can
be provided with the increased bandwidth to the home.
Wireless Relays
Terms: terrestrial microwave relays, repeaters, satellites, footprint, geostationary orbit, C-band, Ku- and
Ka-bands, uplinking, downlinking, low noise amplifier (LNA), down-converter, low noise block
converter (LNB), spot beam, transponders, antennas, power supplies, telemetering devices, small
thrusters, TVROs, Direct Broadcast Satellite (DBS), DIRECTV, C-band, Ku-band
oHow do microwave relay networks work? For example, how do microwave relays differ from
coaxial cable or fiber optics? Use Exhibit 5.c to show how microwaves send material in 30-mile
increments in point-to-point communication.
oWhat advantages do satellites have over microwave relays? One is that satellites can transverse
oceans, mountainous regions, and other inaccessible areas. Note that a signal from a satellite relay
(footprint) can be received by an unlimited number of Earth stations. (See Exhibit 5.f.) It costs no
more to transmit the signal to 200 than to 50 Earth stations. Also, attenuation from satellite relays
is much less than from microwave. Why? (The satellite signal has only about 14 miles of
atmosphere to transverse. Microwave signals must “punch” through the atmosphere along their
Distribution by the Internet
Terms: ARPANET, Internet, NSFnet, hypertext transfer protocol (HTTP), HTML (HyperText Markup
Language), Mosaic, Netscape Navigator, Microsoft Internet Explorer, Firefox, Google Chrome, national
access points (NAPs), Internet exchange points, Voice over Internet Protocol (VoIP), domain name
system, uniform resource locator (URL), digital subscriber line (DSL), World Wide Web, modem, ISP
(Internet Service Provider), ADSL (asymmetric digital subscriber line), WiFi, WiMax, global system for
mobile communications (GSM)
oMany students use the Internet for research. You may want to develop specific assignments using
the ‘Net so students will become familiar with its capabilities. For instance, you may ask them to
research a specific network’s programming or a specific legal pronouncement. Ask them to
download copy used for the assignment and provide you with site information.
oHave students list the different applications the Internet offers. Examples are e-mail, search, e-
commerce, podcasting, blogging, social networking and Web TV. Discuss how these applications
will continue to shape, supplement, or replace the operations of traditional electronic media.
Mobile DTV Services
Terms: mobile TV standard, National Association of Broadcasters, Advanced Television Systems
Committee (ATSC)
oEarly research indicates that viewers are willing to watch program-length shows instead of video
snacking. What are the implications of these results? Have students discuss their preferences in
The Future
Terms: digital bytes, bandwidth, “bandwidth hogs,” ISP, Internet
o Will the Internet be the main delivery vehicle of electronic media? How will developments in
traditional media affect the use of the Internet to deliver audio and video programming? How
PEARSON MYCOMMUNICATIONKIT RESOURCES
Each chapter of the MyCommKit for Head’s Broadcasting in America, 10th Edition includes chapter
learning objectives, practice quizzes, key terms flash card, and select media.
Media available for this chapter:
OUTSIDE AUDIO/VISUAL RESOURCES
A Basic Introduction to Satellites for Beginners (VHS/Beta, 14 min.,
1990)
A 14-minute, fast-paced introduction into the world of communications, satellites, and satellite television
aimed at the novice. It covers fundamentals like how geostationary orbits work and how satellites and
The New Age of Digital Video Compression (VHS, 71 min., 1994)
Examines this new technology in detail using simple language, analogies, and detailed animated graphics.
Basic concepts such as bandwidth are covered, as well as numerous applications and future possibilities.
The World at 12 GigaHertz (VHS, 60 min., 1993)
Overview of Ku-band satellite uses and technology, showing many advantages this frequency band offers.
The Era of Direct Broadcast Satellites (VHS, 56 min., 1993)
Explores DBS and includes DBS services in use in England, Japan, and Australia. History of home
Components of Multimedia (VHS, 29 min., 1995)
Investigates the creation of specific components of digital media including audio, video, graphics, and
The Multimedia Revolution—Today and Tomorrow (VHS, 29 min., 1995)
The Internet Learning Program (VHS, 3 prog./40 min. each, 1996)
This three-part video, plus 200-page guidebook, is an excellent practical teaching tool for students and
teachers. The guidebook contains quizzes and exercises promoting active learning. The program also
Visions of Heaven and Hell: Information
Technology and the Future (VHS, 3 prog./52 min. each,
1996)
This three-program series looks at the people who are selling us the idea of a better future and at the
massive social change that new technology could bring. “Selling the Future” explores the question “Will
Once Upon a Time in Cyberville (VHS, 51 min., 1995)
Frontline: High Stakes in Cyberspace (VHS, 60 min., 1995)
Understanding and Using the Internet (VHS, 120 min., 1995)
This two-hour program explains the history of the world’s largest computer network through the voices of
Virtual Friends: Living in Cyberspace (VHS, 25 min., 2000)
Relationships in the modern megalopolis: interpersonal or impersonal? This program investigates the new