Satellite television is a service that delivers television programming
to viewers by relaying it from a communications satellite orbiting the
Earth directly to the viewer's location. The signals are received
via an outdoor parabolic antenna commonly referred to as a satellite
dish and a low-noise block downconverter.
A satellite receiver then decodes the desired television programme for
viewing on a television set. Receivers can be external set-top boxes,
or a built-in television tuner.
Satellite television provides a wide
range of channels and services. It is usually the only television
available in many remote geographic areas without terrestrial
television or cable television service.
Modern systems signals are relayed from a communications satellite on
Ku band frequencies (12–18 GHz) requiring only a small dish
less than a meter in diameter. The first satellite TV systems were
an obsolete type now known as television receive-only. These systems
received weaker analog signals transmitted in the C-band
(4–8 GHz) from FSS type satellites, requiring the use of large
2–3-meter dishes. Consequently, these systems were nicknamed "big
dish" systems, and were more expensive and less popular.
Early systems used analog signals, but modern ones use digital signals
which allow transmission of the modern television standard
high-definition television, due to the significantly improved spectral
efficiency of digital broadcasting.
Different receivers are required for the two types. Some transmissions
and channels are unencrypted and therefore free-to-air or
free-to-view, while many other channels are transmitted with
encryption (pay television), requiring the viewer to subscribe and pay
a monthly fee to receive the programming.
1.1 Sun outage
2.1 Direct broadcast via satellite
3.1 Early history
3.2 Beginning of the satellite TV industry, 1976–1980
3.3 TVRO/C-band satellite era, 1980–1986
3.4 1990s to present
4 See also
Satellite television dishes in Malaysia.
An Inview Neelix set-top box.
Back view of a linear polarised LNB.
Corrugated feedhorn and LNB on a Hughes
DirecWay satellite dish.
The satellites used for broadcasting television are usually in a
geostationary orbit 37,000 km (23,000 mi) above the earth's
equator. The advantage of this orbit is that the satellite's orbital
period equals the rotation rate of the Earth, so the satellite appears
at a fixed position in the sky. Thus the satellite dish antenna which
receives the signal can be aimed permanently at the location of the
satellite, and does not have to track a moving satellite. A few
systems instead use a highly elliptical orbit with inclination of
+/−63.4 degrees and orbital period of about twelve hours, known as a
Satellite television, like other communications relayed by satellite,
starts with a transmitting antenna located at an uplink facility.
Uplink satellite dishes are very large, as much as 9 to 12 meters (30
to 40 feet) in diameter. The increased diameter results in more
accurate aiming and increased signal strength at the satellite. The
uplink dish is pointed toward a specific satellite and the uplinked
signals are transmitted within a specific frequency range, so as to be
received by one of the transponders tuned to that frequency range
aboard that satellite. The transponder re-transmits the signals
back to Earth at a different frequency (a process known as
translation, used to avoid interference with the uplink signal),
typically in the C-band (4–8 GHz), Ku-band (12–18 GHz),
or both. The leg of the signal path from the satellite to the
receiving Earth station is called the downlink.
A typical satellite has up to 32 Ku-band or 24 C-band transponders, or
more for Ku/C hybrid satellites. Typical transponders each have a
bandwidth between 27 and 50 MHz. Each geostationary C-band
satellite needs to be spaced 2° longitude from the next satellite to
avoid interference; for Ku the spacing can be 1°. This means that
there is an upper limit of 360/2 = 180 geostationary C-band satellites
or 360/1 = 360 geostationary Ku-band satellites. C-band
transmission is susceptible to terrestrial interference while Ku-band
transmission is affected by rain (as water is an excellent absorber of
microwaves at this particular frequency). The latter is even more
adversely affected by ice crystals in thunder clouds.
On occasion, sun outage will occur when the sun lines up directly
behind the geostationary satellite to which the receiving antenna is
pointed. The downlink satellite signal, quite weak after traveling
the great distance (see inverse-square law), is collected with a
parabolic receiving dish, which reflects the weak signal to the dish's
focal point. Mounted on brackets at the dish's focal point is a
device called a feedhorn or collector. The feedhorn is a section
of waveguide with a flared front-end that gathers the signals at or
near the focal point and conducts them to a probe or pickup connected
to a low-noise block downconverter (LNB). The LNB amplifies the
signals and downconverts them to a lower block of intermediate
frequencies (IF), usually in the L-band.
The original C-band satellite television systems used a low-noise
amplifier (LNA) connected to the feedhorn at the focal point of the
dish. The amplified signal, still at the higher microwave
frequencies, had to be fed via very expensive low-loss 50-ohm
impedance gas filled hardline coaxial cable with relatively complex
N-connectors to an indoor receiver or, in other designs, a
downconverter (a mixer and a voltage-tuned oscillator with some filter
circuitry) for downconversion to an intermediate frequency. The
channel selection was controlled typically by a voltage tuned
oscillator with the tuning voltage being fed via a separate cable to
the headend, but this design evolved.
Designs for microstrip-based converters for amateur radio frequencies
were adapted for the 4 GHz C-band. Central to these designs
was concept of block downconversion of a range of frequencies to a
lower, more easily handled IF.
The advantages of using an LNB are that cheaper cable can be used to
connect the indoor receiver to the satellite television dish and LNB,
and that the technology for handling the signal at
L-band and UHF was
far cheaper than that for handling the signal at C-band
frequencies. The shift to cheaper technology from the hardline and
N-connectors of the early C-band systems to the cheaper and simpler
75-ohm cable and F-connectors allowed the early satellite television
receivers to use, what were in reality, modified UHF television tuners
which selected the satellite television channel for down conversion to
a lower intermediate frequency centered on 70 MHz, where it was
demodulated. This shift allowed the satellite television DTH
industry to change from being a largely hobbyist one where only small
numbers of systems costing thousands of US dollars were built, to a
far more commercial one of mass production.
In the United States, service providers use the intermediate frequency
ranges of 950–2150 MHz to carry the signal from the LNBF at the
dish down to the receiver. This allows for transmission of UHF signals
along the same span of coaxial wire at the same time. In some
DirecTV AU9-S and AT-9), ranges of the lower
B-band[ambiguous] and 2250–3000 MHz, are used. Newer LNBFs in
use by DirecTV, called SWM (Single Wire Multiswitch), are used to
implement single cable distribution and use a wider frequency range of
2–2150 MHz.
The satellite receiver or set-top box demodulates and converts the
signals to the desired form (outputs for television, audio, data,
etc.). Often, the receiver includes the capability to selectively
unscramble or decrypt the received signal to provide premium services
to some subscribers; the receiver is then called an integrated
receiver/decoder or IRD. Low-loss cable (e.g. RG-6, RG-11, etc.)
is used to connect the receiver to the LNBF or LNB.
RG-59 is not
recommended for this application as it is not technically designed to
carry frequencies above 950 MHz, but may work in some
circumstances, depending on the quality of the coaxial wire, signal
levels, cable length, etc.
A practical problem relating to home satellite reception is that an
LNB can basically only handle a single receiver. This is because
the LNB is translating two different circular polarizations
(right-hand and left-hand) and, in the case of K-band, two different
frequency bands (lower and upper) to the same frequency range on the
cable. Depending on which frequency and polarization a transponder
is using, the satellite receiver has to switch the LNB into one of
four different modes in order to receive a specific "channel".
This is handled by the receiver using the
DiSEqC protocol to control
the LNB mode. If several satellite receivers are to be attached to
a single dish, a so-called multiswitch will have to be used in
conjunction with a special type of LNB. There are also LNBs
available with a multiswitch already integrated. This problem
becomes more complicated when several receivers are to use several
dishes (or several LNBs mounted in a single dish) pointing to
A common solution for consumers wanting to access multiple satellites
is to deploy a single dish with a single LNB and to rotate the dish
using an electric motor. The axis of rotation has to be set up in the
north-south direction and, depending on the geographical location of
the dish, have a specific vertical tilt. Set up properly the motorized
dish when turned will sweep across all possible positions for
satellites lined up along the geostationary orbit directly above the
equator. The disk will then be capable of receiving any geostationary
satellite that is visible at the specific location, i.e. that is above
the horizon. The
DiSEqC protocol has been extended to encompass
commands for steering dish rotors.
There are five major components in a satellite system: the programming
source, the broadcast center, the satellite, the satellite dish, and
the receiver. "Direct broadcast" satellites used for transmission of
satellite television signals are generally in geostationary orbit
37,000 km (23,000 mi) above the earth's equator. The
reason for using this orbit is that the satellite circles the Earth at
the same rate as the Earth rotates, so the satellite appears at a
fixed point in the sky. Thus satellite dishes can be aimed permanently
at that point, and don't need a tracking system to turn to follow a
moving satellite. A few satellite TV systems use satellites in a
Molniya orbit, a highly elliptical orbit with inclination of +/-63.4
degrees and orbital period of about twelve hours.
Satellite television, like other communications relayed by satellite,
starts with a transmitting antenna located at an uplink facility.
Uplink facilities transmit the signal to the satellite over a narrow
beam of microwaves, typically in the C-band frequency range due to its
resistance to rain fade.
Uplink satellite dishes are very large,
often as much as 9 to 12 metres (30 to 40 feet) in diameter to
achieve accurate aiming and increased signal strength at the
satellite, to improve reliability. The uplink dish is pointed
toward a specific satellite and the uplinked signals are transmitted
within a specific frequency range, so as to be received by one of the
transponders tuned to that frequency range aboard that satellite.
The transponder then converts the signals to Ku band, a process known
as "translation," and transmits them back to earth to be received by
home satellite stations.
The downlinked satellite signal, weaker after traveling the great
distance (see inverse-square law), is collected by using a rooftop
parabolic receiving dish ("satellite dish"), which reflects the weak
signal to the dish's focal point. Mounted on brackets at the
dish's focal point is a feedhorn which passes the signals through
a waveguide to a device called a low-noise block converter (LNB) or
low noise converter (LNC) attached to the horn. The LNB amplifies
the weak signals, filters the block of frequencies in which the
satellite television signals are transmitted, and converts the block
of frequencies to a lower frequency range in the
L-band range. The
signal is then passed through a coaxial cable into the residence to
the satellite television receiver, a set-top box next to the
The reason for using the LNB to do the frequency translation at the
dish is so that the signal can be carried into the residence using
cheap coaxial cable. To transport the signal into the house at its
Ku band microwave frequency would require an expensive
waveguide, a metal pipe to carry the radio waves. The cable
connecting the receiver to the LNB are of the low loss type RG-6, quad
shield RG-6, or RG-11.
RG-59 is not recommended for this
application as it is not technically designed to carry frequencies
above 950 MHz, but will work in many circumstances, depending on
the quality of the coaxial wire. The shift to more affordable
technology from the 50 ohm impedance cable and N-connectors of
the early C-band systems to the cheaper 75 ohm technology and
F-connectors allowed the early satellite television receivers to use,
what were in reality, modified UHF television tuners which selected
the satellite television channel for down conversion to another lower
intermediate frequency centered on 70 MHz where it was
An LNB can only handle a single receiver. This is due to the fact
that the LNB is mapping two different circular polarisations – right
hand and left hand – and in the case of the Ku-band two different
reception bands – lower and upper – to one and the same frequency
band on the cable, and is a practical problem for home satellite
reception. Depending on which frequency a transponder is
transmitting at and on what polarisation it is using, the satellite
receiver has to switch the LNB into one of four different modes in
order to receive a specific desired program on a specific
transponder. The receiver uses the
DiSEqC protocol to control the
LNB mode, which handles this. If several satellite receivers are
to be attached to a single dish a so-called multiswitch must be used
in conjunction with a special type of LNB. There are also LNBs
available with a multiswitch already integrated. This problem
becomes more complicated when several receivers use several dishes or
several LNBs mounted in a single dish are aimed at different
The set-top box selects the channel desired by the user by filtering
that channel from the multiple channels received from the satellite,
converts the signal to a lower intermediate frequency, decrypts the
encrypted signal, demodulates the radio signal and sends the resulting
video signal to the television through a cable. To decrypt the
signal the receiver box must be "activated" by the satellite company.
If the customer fails to pay his monthly bill the box is "deactivated"
by a signal from the company, and the system will not work until the
company reactivates it. Some receivers are capable of decrypting the
received signal itself. These receivers are called integrated
receiver/decoders or IRDs.
Analog television which was distributed via satellite was usually sent
scrambled or unscrambled in NTSC, PAL, or
SECAM television broadcast
standards. The analog signal is frequency modulated and is converted
from an FM signal to what is referred to as baseband. This baseband
comprises the video signal and the audio subcarrier(s). The audio
subcarrier is further demodulated to provide a raw audio signal.
Later signals were digitized television signal or multiplex of
signals, typically QPSK. In general, digital television, including
that transmitted via satellites, is based on open standards such as
MPEG and DVB-S/
DVB-S2 or ISDB-S.
The conditional access encryption/scrambling methods include NDS,
BISS, Conax, Digicipher, Irdeto, Cryptoworks, DG Crypt, Beta digital,
SECA Mediaguard, Logiways, Nagravision, PowerVu, Viaccess,
Videocipher, and VideoGuard. Many conditional access systems have been
An event called sun outage occurs when the sun lines up directly
behind the satellite in the field of view of the receiving satellite
dish. This happens for about a 10-minute period daily around
midday, twice every year for a two-week period in the spring and fall
around the equinox. During this period, the sun is within the main
lobe of the dish's reception pattern, so the strong microwave noise
emitted by the sun on the same frequencies used by the satellite's
transponders drowns out reception.
Direct broadcast via satellite
DBS satellite dishes installed on an apartment complex.
A Sky "minidish".
Direct-To-Home can either refer to the communications satellites
themselves that deliver service or the actual television service.
Most satellite television customers in developed television markets
get their programming through a direct broadcast satellite
provider. Signals are transmitted using
Ku band and are completely
digital which means it has high picture and stereo sound quality.
Programming for satellite television channels comes from multiple
sources and may include live studio feeds. The broadcast center
assembles and packages programming into channels for transmission and,
where necessary, encrypts the channels. The signal is then sent to the
uplink  where it is transmitted to the satellite. With some
broadcast centers, the studios, administration and up-link are all
part of the same campus. The satellite then translates and
broadcasts the channels.
Most systems use the
DVB-S standard for transmission. With pay
television services, the datastream is encrypted and requires
proprietary reception equipment. While the underlying reception
technology is similar, the pay television technology is proprietary,
often consisting of a conditional-access module and smart card. This
measure assures satellite television providers that only authorized,
paying subscribers have access to pay television content but at the
same time can allow free-to-air channels to be viewed even by the
people with standard equipment available in the market.
Some countries operate satellite television services which can be
received for free, without paying a subscription fee. This is called
free-to-air satellite television.
Germany is likely the leader in
free-to-air with approximately 250 digital channels (including 83 HDTV
channels and various regional channels) broadcast from the Astra
19.2°E satellite constellation. These are not marketed as a DBS
service, but are received in approximately 18 million homes, as well
as in any home using the
Sky Deutschland commercial DBS system. All
German analogue satellite broadcasts ceased on 30 April 2012.
United Kingdom has approximately 160 digital channels (including
the regional variations of
BBC channels, ITV channels,
Channel 4 and
Channel 5) that are broadcast without encryption from the Astra
28.2°E satellite constellation, and receivable on any
DVB-S2 receiver is required for certain high definition television
services). Most of these channels are included within the Sky EPG, and
an increasing number within the
India's national broadcaster, Doordarshan, promotes a free-to-air DBS
package as "DD Free Dish", which is provided as in-fill for the
country's terrestrial transmission network. It is broadcast from
GSAT-15 at 93.5°E and contains about 80 FTA channels.
While originally launched as backhaul for their digital terrestrial
television service, a large number of French channels are free-to-air
on satellites at 5°W, and have recently been announced as being
official in-fill for the DTT network.
North America (United States,
Canada and Mexico) there are over 80
FTA digital channels available on
Galaxy 19 (with the majority being
ethnic or religious in nature). Other FTA satellites include AMC-4,
AMC-6, Galaxy 18, and
Satmex 5. A company called
FTA religious broadcasters on Galaxy 19.
A C-band satellite dish used by TVRO systems.
Television receive-only, or TVRO, arose during the early days
of satellite television reception to differentiate it from commercial
satellite television uplink and downlink operations (transmit and
receive). This was the primary method of satellite television
transmissions before the satellite television industry shifted, with
the launch of higher powered DBS satellites in the early 1990s which
transmitted their signals on the
Ku band frequencies. Satellite
television channels at that time were intended to be used by cable
television networks rather than received by home viewers. Early
satellite television receiver systems were largely constructed by
hobbyists and engineers. These early TVRO systems operated mainly on
the C-band frequencies and the dishes required were large; typically
over 3 meters (10 ft) in diameter. Consequently, TVRO is
often referred to as "big dish" or "Big Ugly Dish" (BUD) satellite
TVRO systems were designed to receive analog and digital satellite
feeds of both television or audio from both C-band and Ku-band
transponders on FSS-type satellites. The higher frequency
Ku-band systems tend to resemble DBS systems and can use a smaller
dish antenna because of the higher power transmissions and greater
antenna gain. TVRO systems tend to use larger rather than smaller
satellite dish antennas, since it is more likely that the owner of a
TVRO system would have a C-band-only setup rather than a Ku band-only
setup. Additional receiver boxes allow for different types of digital
satellite signal reception, such as DVB/
MPEG-2 and 4DTV.
The narrow beam width of a normal parabolic satellite antenna means it
can only receive signals from a single satellite at a time.
Simulsat or the Vertex-RSI TORUS, is a quasi-parabolic satellite
earthstation antenna that is capable of receiving satellite
transmissions from 35 or more C- and Ku-band satellites
In 1945 British science fiction writer
Arthur C. Clarke
Arthur C. Clarke proposed a
worldwide communications system which would function by means of three
satellites equally spaced apart in earth orbit. This was
published in the October 1945 issue of the
Wireless World magazine and
won him the Franklin Institute's
Stuart Ballantine Medal in
The first public satellite television signals from
Europe to North
America were relayed via the
Telstar satellite over the
on 23 July 1962, although a test broadcast had taken place almost two
weeks earlier on 11 July. The signals were received and broadcast
in North American and European countries and watched by over 100
million. Launched in 1962, the Relay 1 satellite was the first
satellite to transmit television signals from the US to Japan. The
first geosynchronous communication satellite, Syncom 2, was launched
on 26 July 1963.
The world's first commercial communications satellite, called Intelsat
I and nicknamed "Early Bird", was launched into geosynchronous orbit
on April 6, 1965. The first national network of television
satellites, called Orbita, was created by the
Soviet Union in October
1967, and was based on the principle of using the highly elliptical
Molniya satellite for rebroadcasting and delivering of television
signals to ground downlink stations. The first commercial North
American satellite to carry television transmissions was Canada's
geostationary Anik 1, which was launched on 9 November 1972.
ATS-6, the world's first experimental educational and direct broadcast
satellite (DBS), was launched on 30 May 1974. It transmitted at
860 MHz using wideband FM modulation and had two sound channels.
The transmissions were focused on the Indian subcontinent but
experimenters were able to receive the signal in Western
home constructed equipment that drew on UHF television design
techniques already in use.
The first in a series of Soviet geostationary satellites to carry
Ekran 1, was launched on 26 October
1976. It used a 714 MHz UHF downlink frequency so that the
transmissions could be received with existing UHF television
technology rather than microwave technology.
Beginning of the satellite TV industry, 1976–1980
The satellite television industry developed first in the US from the
cable television industry as communication satellites were being used
to distribute television programming to remote cable television
headends. Home Box Office (HBO),
Turner Broadcasting System
Turner Broadcasting System (TBS), and
Christian Broadcasting Network
Christian Broadcasting Network (CBN, later The Family Channel) were
among the first to use satellite television to deliver programming.
Taylor Howard of
San Andreas, California
San Andreas, California became the first person to
receive C-band satellite signals with his home-built system in
In the US, PBS, a non-profit public broadcasting service, began to
distribute its television programming by satellite in 1978.
In 1979 Soviet engineers developed the Moskva (or Moscow) system of
broadcasting and delivering of TV signals via satellites. They
Gorizont communication satellites later that same year.
These satellites used geostationary orbits. They were equipped
with powerful on-board transponders, so the size of receiving
parabolic antennas of downlink stations was reduced to 4 and 2.5
metres. On October 18, 1979, the Federal Communications Commission
(FCC) began allowing people to have home satellite earth stations
without a federal government license. The front cover of the 1979
Neiman-Marcus Christmas catalogue featured the first home satellite TV
stations on sale for $36,500. The dishes were nearly 20 feet
(6.1 m) in diameter and were remote controlled. The price
went down by half soon after that, but there were only eight more
channels. The Society for Private and Commercial Earth Stations
(SPACE), an organisation which represented consumers and satellite TV
system owners, was established in 1980.
Early satellite television systems were not very popular due to their
expense and large dish size. The satellite television dishes of
the systems in the late 1970s and early 1980s were 10 to 16 feet (3.0
to 4.9 m) in diameter, made of fibreglass or solid aluminum
or steel, and in the United States cost more than $5,000,
sometimes as much as $10,000. Programming sent from ground
stations was relayed from eighteen satellites in geostationary orbit
located 22,300 miles (35,900 km) above the Earth.
TVRO/C-band satellite era, 1980–1986
By 1980, satellite television was well established in the USA and
Europe. On 26 April 1982, the first satellite channel in the UK,
Television Ltd. (later Sky1), was launched. Its signals
were transmitted from the ESA's Orbital Test Satellites. Between
1981 and 1985, TVRO systems' sales rates increased as prices fell.
Advances in receiver technology and the use of gallium arsenide FET
technology enabled the use of smaller dishes. Five hundred thousand
systems, some costing as little as $2000, were sold in the US in
1984. Dishes pointing to one satellite were even cheaper.
People in areas without local broadcast stations or cable television
service could obtain good-quality reception with no monthly
fees. The large dishes were a subject of much consternation,
as many people considered them eyesores, and in the US most
condominiums, neighborhoods, and other homeowner associations tightly
restricted their use, except in areas where such restrictions were
illegal. These restrictions were altered in 1986 when the Federal
Communications Commission ruled all of them illegal. A
municipality could require a property owner to relocate the dish if it
violated other zoning restrictions, such as a setback requirement, but
could not outlaw their use. The necessity of these restrictions
would slowly decline as the dishes got smaller.
Originally, all channels were broadcast in the clear (ITC) because the
equipment necessary to receive the programming was too expensive for
consumers. With the growing number of TVRO systems, the program
providers and broadcasters had to scramble their signal and develop
In October 1984, the U.S. Congress passed the Cable Communications
Policy Act of 1984, which gave those using TVRO systems the right to
receive signals for free unless they were scrambled, and required
those who did scramble to make their signals available for a
reasonable fee. Since cable channels could prevent reception
by big dishes, other companies had an incentive to offer
competition. In January 1986,
HBO began using the now-obsolete
VideoCipher II system to encrypt their channels. Other channels
used less secure television encryption systems. The scrambling of HBO
was met with much protest from owners of big-dish systems, most of
which had no other option at the time for receiving such channels,
claiming that clear signals from cable channels would be difficult to
HBO allowed dish owners to subscribe directly
to their service for $12.95 per month, a price equal to or higher than
what cable subscribers were paying, and required a descrambler to be
purchased for $395. This led to the attack on HBO's transponder
Galaxy 1 by John R. MacDougall in April 1986. One by one, all
commercial channels followed HBO's lead and began scrambling their
channels. The Satellite
Broadcasting and Communications
Association (SBCA) was founded on December 2, 1986 as the result of a
merger between SPACE and the Direct Broadcast Satellite Association
Videocipher II used analog scrambling on its video signal and Data
Encryption Standard–based encryption on its audio signal.
VideoCipher II was defeated, and there was a black market for
descrambler devices which were initially sold as "test" devices.
The necessity for better satellite television programming than TVRO
arose in the 1980s.
Satellite television services, first in Europe,
Ku band signals in the late 1980s. On 11 December
Luxembourg launched Astra 1A, the first satellite to provide
medium power satellite coverage to Western Europe. This was one of
the first medium-powered satellites, transmitting signals in Ku band
and allowing reception with small(90 cm) dishes for the first
time ever. The launch of Astra beat the winner of the UK's state
Direct Broadcast Satellite licence, British Satellite Broadcasting, to
the market, and accelerated its demise.
1990s to present
By 1987, nine channels were scrambled, but 99 others were available
HBO initially charged a monthly fee of $19.95,
soon it became possible to unscramble all channels for $200 a
year. Dish sales went down from 600,000 in 1985 to 350,000 in
1986, but pay television services were seeing dishes as something
positive since some people would never have cable service, and the
industry was starting to recover as a result. Scrambling also led
to the development of pay-per-view events. On November 1, 1988,
NBC began scrambling its C-band signal but left its
Ku band signal
unencrypted in order for affiliates to not lose viewers who could not
see their advertising. Most of the two million satellite dish
users in the United States still used C-band. ABC and
considering scrambling, though
CBS was reluctant due to the number of
people unable to receive local network affiliates. The piracy on
satellite television networks in the US led to the introduction of the
Television Consumer Protection and Competition Act of 1992. This
legislation enabled anyone caught engaging in signal theft to be fined
up to $50,000 and to be sentenced to a maximum of two years in
prison. A repeat offender can be fined up to $100,000 and be
imprisoned for up to five years.
Satellite television had also developed in
Europe but it initially
used low power communication satellites and it required dish sizes of
over 1.7 metres. On 11 December 1988
Luxembourg launched Astra 1A, the
first satellite to provide medium power satellite coverage to Western
Europe. This was one of the first medium-powered satellites,
transmitting signals in
Ku band and allowing reception with small
dishes (90 cm). The launch of Astra beat the winner of the
UK's state Direct Broadcast Satellite licence holder, British
Satellite Broadcasting, to the market.
In the US in the early 1990s, four large cable companies launched
PrimeStar, a direct broadcasting company using medium power
satellites. The relatively strong transmissions allowed the use of
smaller (90 cm) dishes. Its popularity declined with the 1994
launch of the Hughes
Dish Network satellite television
On March 4, 1996
EchoStar introduced Digital Sky Highway (Dish
Network) using the
EchoStar 1 satellite.
EchoStar launched a
second satellite in September 1996 to increase the number of channels
Dish Network to 170. These systems provided better
pictures and stereo sound on 150–200 video and audio channels, and
allowed small dishes to be used. This greatly reduced the popularity
of TVRO systems. In the mid-1990s, channels began moving their
broadcasts to digital television transmission using the DigiCipher
conditional access system.
In addition to encryption, the widespread availability, in the US, of
DBS services such as
DirecTV had been reducing the
popularity of TVRO systems since the early 1990s. Signals from DBS
satellites (operating in the more recent Ku band) are higher in both
frequency and power (due to improvements in the solar panels and
energy efficiency of modern satellites) and therefore require much
smaller dishes than C-band, and the digital modulation methods now
used require less signal strength at the receiver than analog
modulation methods. Each satellite also can carry up to 32
transponders in the Ku band, but only 24 in the C band, and several
digital subchannels can be multiplexed (MCPC) or carried separately
(SCPC) on a single transponder. Advances in noise reduction due to
improved microwave technology and semiconductor materials have also
had an effect. However, one consequence of the higher frequencies
used for DBS services is rain fade where viewers lose signal during a
heavy downpour. C-band satellite television signals are less prone to
In a return to the older (but proven) technologies of satellite
communication, the current DBS-based satellite providers in the USA
Dish Network and DirecTV) are now utilizing additional capacity on
the Ku-band transponders of existing FSS-class satellites, in addition
to the capacity on their own existing fleets of DBS satellites in
orbit. This was done in order to provide more channel capacity for
their systems, as required by the increasing number of High-Definition
and simulcast local station channels. The reception of the channels
carried on the Ku-band FSS satellite's respective transponders has
been achieved by both
Dish Network issuing to their
subscribers dishes twice as big in diameter (36") than the previous
18" (& 20" for the
Dish Network "Dish500") dishes the services
used initially, equipped with 2 circular-polarized LNBFs (for
reception of 2 native DBS satellites of the provider, 1 per LNBF), and
1 standard linear-polarized LNB for reception of channels from an
FSS-type satellite. These newer DBS/FSS-hybrid dishes, marketed by
Dish Network as the "SlimLine" and "SuperDish" models
respectively, are now the current standard for both providers, with
their original 18"/20" single or dual LNBF dishes either now obsolete,
or only used for program packages, separate channels, or services only
broadcast over the providers' DBS satellites.
On 29 November 1999 US President
Bill Clinton signed the Satellite
Home Viewer Improvement Act (SHVIA). The act allowed Americans to
receive local broadcast signals via direct broadcast satellite systems
for the first time.
Television for the Asian Region (STAR), a service based in
Hong Kong which now provides satellite TV coverage to Asia
and Australia, introduced satellite TV to the Asian region in the
early 1990s. It began broadcasting signals using the AsiaSat 1
satellite on 1 January 1991.
List of direct broadcast satellite providers
Satellite television by region
Commercialization of space
Satellite subcarrier audio
Smart TV: provides television via internet connection
Radio Regulations, Section IV.
Radio Stations and Systems –
Article 1.39, definition: Broadcasting-satellite service
^ a b "Frequency letter bands". Microwaves101.com. 25 April
^ a b c "Installing Consumer-Owned Antennas and Satellite Dishes".
FCC. Retrieved 2008-11-21.
^ Campbell, Dennis; Cotter, Susan (1998). Copyright Infringement.
Kluwer Law International. ISBN 90-247-3002-3. Retrieved 18
^ a b c d Pattan 1993, p. 207.
^ Pattan 1993, p. 330.
^ Pattan 1993, p. 327.
^ a b Mott, Sheldon 2000, p. 253.
^ a b Mott, Sheldon 2000, p. 268.
^ a b Mott, Sheldon 2000, p. 115.
^ Tirro 1993, p. 279.
^ Minoli 2009, p. 60.
^ Minoli 2009, p. 27.
^ a b c d Minoli 2009, p. 194.
^ a b c "Europe's Best Kept Secret". Electronics World + Wireless
World. Reed Business Publishing. 95: 60–62. 1985. Retrieved 28 July
^ a b "
Microstrip Impedance Program". Ham
Communications Technology, Incorporated. 17: 84. 1984. Retrieved 28
^ a b c "
Microwave Journal International".
International. Horizon House. 43 (10-12): 26–28. 2000. Retrieved 28
^ Dodd 2002, p. 308.
^ Dodd 2002, p. 72.
^ a b c d e f g h i j k l m n Fox, Barry (1995). "Leaky dishes drown
out terrestrial TV". New Scientist. Reed Business Information. 145:
19–22. Retrieved 28 July 2014.
^ a b c d e f g Pattan, Bruno (31 March 1993). Satellite
Systems:Principles and Technologies. Berlin: Springer Science &
Business Media. ISBN 9780442013578. Retrieved 29 July 2014.
^ a b c d Minoli, Daniel (3 February 2009). Satellite Systems
Engineering in an IPv6 Environment. Boca Raton, Florida: CRC Press.
ISBN 978-1420078688. Retrieved 29 July 2014.
^ a b "
Microwave Journal International".
International. Horizon House. 43 (10–12): 26–28. 2000. Retrieved
28 July 2014.
^ a b c d Dodd, Annabel Z. (2002). The Essential Guide to
Telecommunications (5th ed.). Upper Saddle River, New Jersey: Prentice
Hall. pp. 307–10. ISBN 0130649074. Retrieved 29 July
^ a b Tirró, S. (30 June 1993). Satellite Communication Systems
Design. Berlin: Springer Science & Business Media.
pp. 279–80. ISBN 978-0306441479. Retrieved 29 July
^ a b c Antipolis, Sophia (September 1997). Digital Video Broadcasting
(DVB); Implementation of Binary Phase Shift Keying (BPSK) modulation
in DVB satellite transmission systems (PDF) (Report). European
Telecommunications Standards Institute. pp. 1–7. TR 101 198.
Retrieved 20 July 2014.
^ "JEDI Innovation report".
^ Bruce R. Elbert (2008). "9 Earth Stations and Network Technology".
Introduction To Satellite Communications. Artech House.
^ "Space TV". Popular Mechanics. Hearst Magazines. 171 (8): 57–60.
August 1994. ISSN 0032-4558.
Intelsat New Media Brochure" (PDF).
^ "Satellitenfernsehen in Deutschland" [Satellite TV in Germany].
kabelfernsehen-kabelanschluss.de (in German). Retrieved 5 April
^ "ZDFneo, 3sat, BR, NDR, SWR, WDR, Phoenix, KiKa starten HD Kanäle"
[ZDFneo, 3sat, BR, NDR, SWR, WDR, Phoenix, KiKa launch HD channels].
kabel-internet-telefon.de (in German). 13 March 2012. Retrieved 8
^ "HDTV: Neue HD-Kanäle von ARD und ZDF ab 30. April 2012" [HDTV: New
HD channels from ARD and ZDF after 30 April 2012]. T-online.de (in
German). 20 January 2012. Retrieved 8 April 2012.
^ James, Meg.
NBC tacks on Telemundo oversight to Gaspin's tasks. Los
Angeles Times, July 26, 2007. Retrieved on May 14, 2010.
^ "Satellite Communications Training from NRI!". Popular Science.
Bonnier Corporation. 228. February 1986. Retrieved 16 December
^ Prentiss 1989, p. 274.
^ Prentiss 1989, p. 246.
^ Prentiss 1989, p. 1.
^ Prentiss 1989, p. 293.
^ "Sensing SATCOM Success Is New
Simulsat From ATCi". Satnews. 1
November 2009. Retrieved 16 December 2014.
Arthur C. Clarke
Arthur C. Clarke Foundation". Archived from the original on
July 25, 2011. Retrieved 2016-06-01.
^ Campbell, Richard; Martin, Christopher R.; Fabos, Bettina (23
February 2011). Media and Culture: An Introduction to Mass
Communication. London, UK: Macmillan Publishers. p. 152.
ISBN 978-1457628313. Retrieved 15 August 2014.
^ The 1945 Proposal by
Arthur C. Clarke
Arthur C. Clarke for Geostationary Satellite
^ Wireless technologies and the national information infrastructure.
DIANE Publishing. September 1995. p. 138. ISBN 0160481805.
Retrieved 15 August 2014.
^ a b Klein, Christopher (23 July 2012). "The Birth of Satellite TV,
50 Years Ago". History.com. History Channel. Retrieved 5 June
^ "Relay 1". NASA.gov. NASA.
^ Darcey, RJ (16 August 2013). "Syncom 2". NASA.gov. NASA. Retrieved 5
^ "Encyclopedia Astronautica -
Intelsat I". Archived from the original
on 16 January 2010. Retrieved 5 April 2010.
^ "Soviet-bloc Research in Geophysics, Astronomy, and Space" (Press
release). Springfield Virginia: U.S. Joint Publications Research
Service. 1970. p. 60. Retrieved 16 December 2014.
^ Robertson, Lloyd (1972-11-09). "Anik A1 launching: bridging the
gap". CBC English TV. Retrieved 2007-01-25.
^ Ezell, Linda N. (22 January 2010). "
NASA - ATS". Nasa.gov. NASA.
Retrieved 1 July 2014.
^ Long Distance
Television Reception (TV-DX) For the Enthusiast, Roger
W. Bunney, ISBN 0900162716
^ "Ekran". Astronautix.com. Astronautix. 2007. Archived from the
original on 12 November 2013. Retrieved 1 July 2014.
^ Feder, Barnaby J. (15 November 2002). "Taylor Howard, 70, Pioneer In
Satellite TV for the Home". New York Times. Retrieved 19 July
^ Public Service
Broadcasting in the Age of Globalization, Editors:
Indrajit Banerjee, Kalinga Seneviratne. ISBN 9789814136013
^ a b Wade, Mark. "Gorizont". Encyclopedia Astronautica. Archived from
the original on 2008-06-17. Retrieved 2008-06-29.
^ The "Glory Days" of Satellite Archived 2014-03-03 at the Wayback
^ Browne, Ray (2001). The Guide to United States Popular Culture.
Madison, Wisconsin: Popular Press. p. 706.
ISBN 9780879728212. Retrieved 1 July 2014.
^ Giarrusso, Michael (28 July 1996). "Tiny Satellite Dishes Sprout in
Los Angeles Times. Los Angeles:
Los Angeles Times.
Retrieved 1 July 2014.
^ Keating, Stephen (1999). "Stealing Free TV, Part 2". The Denver
Post. Denver, CO: The Denver Post. Retrieved 3 July 2014.
^ Stein, Joe (1989-01-24). "Whatta dish : Home satellite
reception a TV turn-on". Evening Tribune. p. C-8.
^ "Earth Station Is Very Popular Dish". Reading Eagle. Kansas City,
Missouri. 21 December 1980. Retrieved 21 July 2014.
^ a b c d Brooks, Andree (10 October 1993). "Old satellite dish
restrictions under fire New laws urged for smaller models". The
Baltimore Sun. Baltimore, MD: The Baltimore Sun. Retrieved 1 July
^ a b Nye, Doug (14 January 1990). "SATELLITE DISHES SURVIVE GREAT
SCRAMBLE OF 1980S". Deseret News. Salt Lake City: Deseret News.
Retrieved 30 June 2014.
^ Ku-Band Satellite TV: Theory, Installation and Repair. Frank Baylin
et al. ISBN 9780917893148.
^ a b c Stecklow, Steve (1984-07-07). "America's Favorite Dish". The
Miami Herald. Knight-Ridder News Service. p. 1C.
^ Reibstein, Larry (1981-09-27). "Watching TV Via Satellite Is Their
Dish". The Philadelphia Inquirer. p. E01.
^ a b c Dawidziak, Mark (1984-12-30). "Satellite TV Dishes Getting
Good Reception". Akron Beacon-Journal. p. F-1.
^ a b "Broadband Cable 10th Anniversary". TinyPic. Retrieved 5 May
^ a b "Industry History". sbca.com. Satellite
Communications Association. 2014. Retrieved 5 June 2014.
^ Stecklow, Steve (1984-10-25). "Research Needed in Buying Dish: High
Cost Is Important Consideration for Consumer". Wichita Eagle.
Knight-Ridder News Service. p. 6C.
^ a b c d e Takiff, Jonathan (1987-05-22). "Satellite TV Skies
Brighten As War With Programmers Ends". Chicago Tribune. Knight-Ridder
Newspapers. Retrieved 2014-04-10.
^ Wolf, Ron (1985-01-20). "Direct-Broadcast TV Is Still Not Turned
On". The Philadelphia Inquirer. p. C01.
^ a b c Lyman, Rick; Borowski, Neill (April 29, 1986). "On The Trail
Of 'Captain Midnight'". Philly. Retrieved May 20, 2014.
^ a b Paradise, Paul R. (1 January 1999). Trademark Counterfeiting,
Product Piracy, and the Billion Dollar Threat to the U.S. Economy.
Westport, Connecticut: Greenwood Publishing Group. p. 147.
ISBN 1567202500. Retrieved 3 July 2014.
^ a b c "ASTRA 1A Satellite details 1988-109B NORAD 19688". N2YO. 9
July 2014. Retrieved 12 July 2014.
^ a b c "Scrambled
NBC Bad News for Satellite Pirates". The San
Francisco Chronicle. United Press International. 1988-11-03.
^ a b Article STATUTE-106-Pg1460.pdf, Cable
Protection and Competition Act of 1992, Act No. 1460 of 8 October
1992 (in English). Retrieved on 3 July 2014.
^ a b "ASTRA 1A Satellite details 1988-109B NORAD 19688". N2YO. 9 July
2014. Retrieved 12 July 2014.
^ a b Grant, August E. Communication Technology Update (10th ed.).
Taylor & Francis. p. 87. ISBN 978-0-240-81475-9.
^ Bell-Jones, Robin; Berbner, Jochen; Chai, Jianfeng; Farstad, Thomas;
Pham, Minh (June 2001). "High Technology Strategy and
Entrepreneurship" (PDF). INSEAD journal. Fontainebleau: INSEAD.
Archived from the original (PDF) on 2014-07-24.
^ Mirabito, M., and Morgenstern, B. (2004). Satellites: Operations and
Applications: The New Communication Technologies (fifth edition).
Burlington: Focal Press.
^ a b Khaplil, Vidya R.; Bhalachandra, Anjali R. (April 2008).
Advances in Recent Trends in Communication and Networks. New Delhi:
Allied Publishers. p. 119. ISBN 1466651709. Retrieved 16
^ "Rain fade: satellite TV signal and adverse weather".
Dish-cable.com. Dish-cable.com. 2010. Retrieved 16 July 2014.
^ a b Satellite Home Viewer Improvement Act, Act No. 00-96 of 29
November 1999 (in english language). Retrieved on 30 July 2014.
Media related to
Satellite television at Wikimedia Commons
Internet television and radio (Webcast
BitTorrent television and movies)
Pirate radio / Pirate television
Adult television channels
Children's interest channel / Children's television series
Men's interest channel
Movie television channels
Music radio / Music television
Sports television channels
Women's interest channel
Broadcast television systems
Digital on-screen graphic
Television news screen layout
Cable, satellite, and other specialty television providers
Cable, satellite, and other specialty television providers in Africa,
Asia, the Middle East and Oceania
Botswana Cable Network
Cable TV Hong Kong
Lanka Broadband Networks(Sri Lanka)
Montage Cable TV(Nigeria)
Orange Ivory Coast
Top TV (Indonesia)
United Communication Service
Vodafone New Zealand
Airtel digital TV
beIN(Middle East and North Africa)
BiG TV (Indonesia)
DD Free Dish
Dialog TV(Sri Lanka)
Dish TV Sri Lanka
ME Digital TV
OSN(Middle East and North Africa)
Broadcasting Services Fiji
Pearl Digital TV
Pra International Green Group India
Reliance Digital TV
Television (New Zealand)
STAR (Greater China)
StarSat, South Africa
Sky on demand
PEO TV(Sri Lanka)
Saudi Telecom Company
ABS-CBN TV Plus
Freeview (New Zealand)
Dream Satellite TV (Philippines)
Mega TV (Malaysia)
UBI World TV(Australia)
Africa, Asia, Middle East and Oceania
Central and South America
Cable, satellite, and other specialty television providers in Canada
Terrestrial and satellite
Telus Satellite TV
Cablevision for Val-d'Or, QC, MTS for Manitoba)
Cogeco (Ontario, Quebec)
EastLink (Atlantic, Northern Ontario, Western Canada)
Rogers Cable (Ontario, New Brunswick, Newfoundland)
Source (Hamilton, ON)
Shaw (Western Canada, Northwestern Ontario)
Cable Axion (Magog, QC)
CityWest (Prince Rupert, BC)
DERYtelecom (Saguenay, QC)
Novus Cable (select areas of BC Lower Mainland)
Omineca Cablevision (Prince George, BC)
Westman (Brandon, MB)
Defunct cable and DBS companies of Canada
Telus Optik TV
Tbaytel Digital TV
Africa, Asia, and Oceania
1More than 400,000 television service subscribers.
Cable, satellite, and other speciality television providers in Europe
ASK CATV (Bosnia and Herzegovina)
Canal Digital (Norway)
Com Hem (Sweden)
dna Welho (Finland)
ELTA-KABEL (Bosnia and Herzegovina)
Kabel Deutschland (Germany)
Meo (telecommunication service)
MISS.NET (Bosnia and Herzegovina)
Orange TV (France)
RCS & RDS (Romania)
Sat Film (Poland)
Serbia Broadband (Serbia)
Tango TV (Luxembourg)
Tele Columbus (Germany)
Telemach (Bosnia and Herzegovina, Montenegro and Slovenia)
Turksat Kablo TV (Turkey)
UPC Magyarország (Hungary)
UPC Polska (Poland)
Virgin TV (UK)
Virgin Media Ireland
Canal Digital (Denmark, Sweden, Norway and Finland)
Canal (France, Swtizerland)
Cosmote TV (Greece)
Cyfrowy Polsat (Poland)
DIGI (Romania, Hungary)
Focus Sat (Romania)
Freesat from Sky (UK)
Magio TV (Slovakia)
NTV Plus (Russia, Ukraine)
Orange S.A. (France, Belgium)
Sky (Germany, Austria)
Skylink (Slovakia, Czech Republic)
TéléSAT Numérique (Belgium, Luxembourg)
Tivù Sat (Italy)
Total TV (Balkans)
Tricolor TV (Russia, Ukraine)
TV Vlaanderen Digitaal
TV Vlaanderen Digitaal (Belgium)
UPC Direct (Hungary)
Viasat (Denmark, Sweden, Norway, Finland, Latvia, Estonia and
Vip TV (Croatia)
A1 Telekom Austria
BT TV (UK)
Cosmote TV (Greece)
HOME.TV (Bosnia and Herzegovina)
Infostrada TV (Italy)
Magnet Networks (Ireland)
Moja TV (Bosnia and Herzegovina)
Mts TV (Serbia)
Meo (telecommunication service)
IPTV (Bosnia and Herzegovina)
Optimus Clix (Portugal)
Proximus TV (Belgium)
Smart Telecom (Ireland)
SUPER TV (Bosnia and Herzegovina)
TalkTalk TV (UK)
Telekom Entertain (Germany)
Antena PLUS (Serbia)
Boxer TV Access (Sweden)
Boxer TV A/S (Denmark)
Easy TV (Ireland)
KPN Digitenne (Netherlands)
Mediaset Premium (Italy)
Vip TV (Macedonia)
Zala TV (Belarus)
Alice Home TV
Boom TV (Romania)
On Telecoms (Greece)
Cable, satellite, and other specialty television providers in Latin
America and the Caribbean
Axtel TV (Mexico)
Airlink Communications (Trinidad and Tobago)
Digicel Play (Caribbean)
Independent Cable Network of Trinidad and Tobago (ICNTT)
Izzi Telecom (Mexico)
Massy Communications (Trinidad and Tobago)
Mayaro Cable TV (Trinidad and Tobago)
Movistar TV (Chile, Colombia, Peru and Venezuela)
Mundo Pacifico (Chile)
Oi TV (Brazil)
Red Intercable (Argentina)
RVR International (Trinidad and Tobago)
Telefónica del Sur
Tricom (Dominican Republic)
TRICO Industries Limited (Trinidad and Tobago)
CanalSat Caraïbes (Caribbean)
DirecTV (South America & Caribbean)
Green Dot (Caribbean)
Movistar TV (Chile, Colombia, Peru and Venezuela)
Oi TV (Brazil)
SKY México, Dominican Republic & Central America
Vivo TV (Brazil)
bmobile (Trinidad and Tobago)
Claro República Dominicana
Vivo TV (Brazil)
Multi-Choice TV (Barbados)
GVT TV (Brazil)
Vivo TV Plus (Brazil)
Africa, Asia, and Oceania
Cable, satellite, and other specialty television providers in the
Blue Ridge Communications
Hood Canal Communications
Liberty Puerto Rico
Headend in the Sky
Fiber MVPD / IPTV
CenturyLink Prism TV
Cincinnati Bell FiOptics
NEP Datastream TV
North State Communications
Hulu with Live TV
Spectrum TV Stream
Xfinity Instant TV
Apple iTunes Store
CBS All Access
Hallmark Movies Now
Lifetime Movie Club
UFC Fight Pass
Adelphia Communications Corporation
Alameda Power and Telecom1
Bright House Networks
Community Home Entertainment
Graceba Total Communications
TelePrompTer/Group W Cable
Time Warner Cable
1 – Still in operation, but no longer offers cable or
part of its services
GlobeCast World TV
United States Satellite Broadcasting
Voom HD Networks
Virtual Digital Cable
Defunct virtual MVPD
Additional resources on North American television
List of local television stations in North America
North American TV mini-template
List of Canadian television networks
List of Canadian television channels
List of Canadian specialty channels
Local Canadian TV stations
List of United States stations available in Canada
2001 Vancouver TV realignment
Canada broadcast TV realignment
Local Mexican TV stations
List of American cable and satellite networks
List of American over-the-air networks
Local American TV stations (W)
Local American TV stations (K)
Spanish-language TV networks
1994 United States broadcast TV realignment
2006 United States broadcast TV realignment
List of Canadian television stations available in the United States
Insular Areas TV
Africa, Asia, Middle East and Oceania
Wireless video and data distribution methods
Advanced Wireless Services
Digital terrestrial television
Digital terrestrial television (DTT or DTTV)
Digital Video Broadcasting
Multipoint Video Distribution System (
MVDS or DVB-MS)
Television Fixed Service (ITFS; now known as Educational
Broadband Service (EBS))
Local Multipoint Distribution Service (LMDS)
Mobile WiMAX (IEEE 802.16e)
Mobile broadband wireless access (IEEE 802.20)
Multichannel Multipoint Distribution Service
Multichannel Multipoint Distribution Service (MMDS; now known as
Radio Service (BRS))
Multimedia Broadcast Multicast Service (3G MMMS)
UWB (IEEE 802.15.3)
Visual sensor network
Wi-Fi (IEEE 802.11)
WiMAX (IEEE 802.16)
WRAN (IEEE 802.22)
Wireless local loop (WLL)
3GPP Long Term Evolution
3GPP Long Term Evolution (LTE)
Satellite data unit
Satellite radio / TV
Digital audio radio service
Astra Digital Radio
Sirius XM Holdings
Sirius Satellite Radio
Relay satellite companies
Thales Alenia Space
Consultative Committee for Space Data Systems
ETSI Satellite Digital Radio
List of communications satellite firsts
List of communication satellite companies
Cable protection system
Prepay mobile phone
Timeline of communication technology
Undersea telegraph line
Edwin Howard Armstrong
John Logie Baird
Alexander Graham Bell
Jagadish Chandra Bose
Lee de Forest
Erna Schneider Hoover
Charles K. Kao
Alexander Stepanovich Popov
Johann Philipp Reis
Vladimir K. Zworykin
Free-space optical communication
Network switching (circuit
Public Switched Telephone
World Wide Web