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Lecture#06
Networks of radio and television broadcasting
The Bonch-Bruevich Saint-Petersburg State University of Telecommunications
Series of lectures “Telecommunication networks”
Instructor: Prof. Nikolay Sokolov, e-mail: [email protected]
Importance of the broadcastingTime of the information extraction:
•television – 43%,•radio – 39%,•Internet – 5%,•books – 3%.•Others – 10%.
Source: www.iks-media.ru
One of the first Russian TV set
(designed in 1949)
Tube
radio
Radio broadcasting system
Invention of the radio has stimulated organization of the sound broadcasting system. Before wide distribution of the television, radio broadcasting was the only transmission facility for prompt information delivery to the big number of subscribers simultaneously. First radio broadcasting networks have proved high efficiency of the new type of telecommunications. Soon radio broadcasting networks became widely adopted in all developed countries. Important peculiarity of the radio broadcasting as opposed to telegraph and telephone communications systems is the utilization of the one-sided (simplex) channels for the information transmission.
Classification of the radio broadcasting systems
Sound broadcasting
By radio channels By wire communication channels
Analogous
Digital
Single-program
Multiprogram
Mono
Stereo
Ultra-short waves
Long and medium waves
Short waves
Structures of the wire broadcastingAmplifier SL
SL
Subscriber line (SL), 30 V
subscriber's units
One-level network of wire
broadcasting
Two-level network of wire
broadcasting
Amplifier FD
FD
Feeder line (FD), 240 V
subscriber's units
transformer
subscriber's units
transformer
Channels for the radio broadcasting
In Russia, three types of channels are used:
•from 30 to 15000 Hz,
•from 50 to 10000 Hz,
•from 100 to 6000 Hz.
For stereophonic broadcasting two channels (“A” and “B”) are used.
In some broadcasting systems, there is reverse channel. This channel is used for the management and measurement of the QoS parameters.
Typical structure of the radio and television broadcasting networks
Served area
Main Center
Regional Center
Regional Center
Regional Center
Local Centers
Main path Main path
Main path
Standby path
Eye structure
1. Sclera
2. Cornea
3. Anterior chamber
4. Iris
5. Pupil
6. Crystalline lens
7. Optic nerve
8. Retina
Classification of the television broadcasting systems
Television broadcasting
On-air broadcasting
Analoguechannels
Digital channels
Standard quality television
High definition television
Cable television Satellite television Combined system
One-way broadcasting
Interactive television
Video signal spectrum
f, MHz
Picture channel
8.0
0.5
Accompanying sound
7.5
Operational units of the television broadcast
TT
TBU CG
VA Tr Rc
CC TBU
PT
Communication channel
TT – television tube, TBU – time-base unit, CG – clock generator, VA – videoamplifier, Tr – transmitter, Rc – receiver, CC – clock channel, PT – picture tube.
Methods of the television broadcast
SPC
SPC
SPC
.
.
.
CRW
RTE
BMN
WBCN
.
.
.
ETB
BTE
MLE
.
.
.
SPC – sound-production complex, CWR – central switch room, RTE – radio transmitting equipment, BMN – broadcasting main node, WBCN – wire broadcasting central node, ETB – Earth terminal for broadcasting, BTE – broadcasting trunk exchange, MLE – microwave-link equipment.
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Digital television (1)
Digital television (DTV) supports many different picture formats defined by the combination of size, aspect ratio (width to height ratio) and interlacing. The range of formats can be broadly divided into two categories: HDTV and SDTV. These terms by themselves are not very precise, and many subtle intermediate cases exist.
The pixel is the smallest addressable screen element; it is the smallest unit of picture that can be controlled. Each pixel has its own address. The address of a pixel corresponds to its coordinates. Pixels are normally arranged in a two-dimensional grid, and are often represented using dots or squares. Each pixel is a sample of an original image; more samples typically provide more accurate representations of the original. The intensity of each pixel is variable. In color image systems, a color is typically represented by three or four component intensities such as red, green, and blue, or cyan, magenta, yellow, and black.
Digital television (2)
Standard definition TV (SDTV), by comparison, may use one of several different formats taking the form of various aspect ratios depending on the technology used in the country of broadcast. For 4:3 aspect-ratio broadcasts, the 640 × 480 format is used in NTSC countries, while 720 × 576 format is used in PAL countries.
High-definition television (HDTV), one of several different formats that can be transmitted over DTV, uses different formats, amongst which: 1280 × 720 pixels or 1920 × 1080 pixels. Each of these utilizes a 16:9 aspect ratio. HDTV cannot be transmitted over current analog channels.
Evolution of the interactive services
Time
Level of interactive
PpV
SoD
VoD
Videogames
NVoD
PpC
TV broadcasting
PpC – Pay per ChannelPpV – Pay per ViewNVoD – Near Video on DemandVoD – Video on DemandSoD – Services on Demand
Prospects of the radio and television broadcasting development
Among variety of development trends of radio and television broadcasting systems, three important directions should be noted. The first direction is generated by the processes of integration and convergence in the infocommunication system. Consequence of this process is provision of sound and television broadcasting based on the NGN concept. Transfer to the IP broadcasting can be considered as the demonstration of this tendency.The second direction is related to interactivity support, which was absent in radio and television broadcasting systems. Interactivity allows a user to receive, in full measure, the needed services. Already utilized Video on Demand service can serve as an example of such capability.The third direction reflects tendencies to quality. Such tendencies are expressed in the growing sales share of the high-quality television and radio equipment for use in households and in cars. Also requirements to handheld terminals are rising. The same reasons have stimulated HDTV standard development.
Some important aspects of the TV (1)
IPTV:
•additional income ~ 50% of the all respondents,
•growth of the customer’s number ~ 30% of the all respondents,
•growth of the broadband access market ~ 16% of the all respondents,
•retention of the customers ~ 11% of the all respondents.
Source: K. Wieland. What role for IPTV. – Telecommunications International, September, 2006.
Some important aspects of the TV (2)
Mobile TV:
Types of the content:•24% – documentary, sport, and similar programs, •30% – serials,•46% – news.
Place of viewing: •36% – at home,•23% – at work,•21% – in a bus,•7% – in a car,•3% – at bus station.
Some important aspects of the TV (3)
Some important aspects of the TV (4)
Some important aspects of the TV (5)
Some important aspects of the TV (6)
Some important aspects of the TV (7)
Some important aspects of the TV (9)
Some important aspects of the TV (8)
Source: http://spectrum.ieee.org/consumer-electronics/audiovideo/3d-in-the-home
3-D in the Home:
Instructor: Prof. Nikolay Sokolov, e-mail: [email protected]
Questions?
Networks of radio and television broadcasting
