Presentation on t.v. Broadcasting

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TRAINING REPORT ONT.V. BROADCASTINGSubmitted By:-CHANDAN KUMAR JHA

BRANCH: ECE(5th SEM)Roll No.-3108211

COLLEGE: S.I.E.TSESSION: 2008-2012

CITY: AMBALAHARYANA



` ESPN STAR Sports is Asiaâ¼s No. 1 sports broadcaster and content provider, deliveringan array of international and regional sports to viewers via its encrypted pay and free-to-air services. In order to make it a reality, we need to keep on attracting the brightest, mostcreative and talented people. People just like you!

` ESPN STAR Sports showcases sports from around the globe 24 hours a day to acumulative reach of more than 310 million viewers in 24 Asian countries, through 17networks â¼³ each localized to deliver differentiated world-class programming.

` ESPN STAR Sports also delivers sports news and interactive content on digital mediaplatforms including www.espnstar.com, www.espnstar.com.cn, www.espnstar.com.tw,mobileESPN and STAR Sports Mobile. In addition, its Event Management Group managesand promotes premier sporting events in Asia.

` ESPN STAR Sports is a 50:50 joint venture between two of the world's leading cableand satellite broadcasters. As Asia's definitive and complete sports broadcaster andcontent provider, ESPN STAR Sports combines the strengths and resources of itsparent companies ± Walt Disney (ESPN, Inc.) and News Corporation Limited (STAR) ± to deliver a diverse array of international and regional sports to viewers via its

encrypted pay services.



` B

roadcasting is the distribution of audio and video content to adispersed audience via radio, television, or other, often digitaltransmission media. Receiving parties may include the generalpublic

` Television broadcasting (experimentally from 1925, commerciallyfrom the 1930s): this video-programming medium was long-awaitedby the general public and rapidly rose to compete with its older radio-broadcasting sibling.

` Cable radio (also called "cable FM", from 1928) and cabletelevision (from 1932): both via coaxial cable, serving principally astransmission mediums for programming produced at either radio or television stations, with limited production of cable-dedicatedprogramming.

` Satellite television (from c ir c a 1974) and satellite

radio (fromc ir c a

1990): meant for direct-to-home broadcastprogramming (as opposed to studio network uplinks anddownlinks), provides a mix of traditional radio or televisionbroadcast programming, or both, with satellite-dedicatedprogramming.



` TERRESTRIAL.

` CABLE T.V.

` SATELLITE BROADCASTING.



` It is form of T.V. Transmission over the air bytransmitter based on ground, just like doordarshan. It is the oldest form of T.V. broadcasting. Thedrawback with terrestrial broadcasting are:

1)Limited area of coverage.

2)High cost of transmission per square kilometer of coverage.

3)Less number of channel.

4)Susceptible to ghosting. In India T.V. programmes are in PAL

formate.Other major formats in world are NTSC andSECAM.

The T.V. channels in PAL format aregrouped into band as mention below:

BAND I or VHF-I or VHF-L :channel 2 to 4BAND III or VHF-III or VHF-H :channel 5 to 12BAND U or UHF :channel 21 to 69



` It is form of T.V. delivery system (some time alsocalled CATV) in which terrestrial , satellitebroadcast signal are received at headend andmixed with in-house signal source like VCR¶s ,computers etc. and delivered to subscriber¶s T.V.at home via co-axial cables.

Advantage associated with cable T.V. are:

1)Large number of channels can be transmitted.

2)Local information can be sent to viewers.

3)Transmission of pay channels is possible.

4)Superfast internet access will be available soon.

The Band of CATV systems are all theTerrestrial Broadcasting Bands plus Mid-band,

Super band and Hyper band consisting of channels X to S10,S11 to S20 and S21 to S41respectively



` It is form of T.V. transmission beamed from aSATELLITE located in space in an orbit called

GEOSTATIONARY ORBIT. Dish antennas located onground with in the FOOTPRINT of the satellite canreceive the T.V. signal. The T.V. programm areUPLINKED to the satellite from large dish antennacalled EARTH STATION. The path of signal from thesatellite to the receiving dish antenna is called theDOWNLINK.

The advantages are:

1) low cost of transmission per square kilometer of the coverage due to large area of coverage.

2) Large number of channels.

3)High quality picture and sound .no ghosting

4) pay channels possible.

The popular Satellite Downlink channels aregrouped into Band as mentioned below:

S BAND :2.5 to 2.7 GHz

C BAND :3.7 to 4.2GHz

Extended C BAND :3.4 to 3.7GHz



` A satellite lying in thegeostationary orbit has aperiod of rotation of 24hours which matches thatof the earth below. It thus

appear to remain fixed over a given longitude on theearth below. Spacecraftbelow this orbit move faster than the rotational speed of

the earth; those that orbitabove move more slowlythan the rotation of theearth.



` The satellites antenna transmit the TV

signal in a particular shape , called afootprint, pointed at its coverage area.Each satellite has its on characteristicfootprint, with the signal strongest at thecenter and diminishing outward from there.Those who live in a center of the footprintcan receive the signal with a smaller dishantenna than those out on the edges. Aperson in Japan may need a 10-foot

antenna to receive the same qualitypicture as an individual in Thailand with an ±footer. The most common home satellitedishes are 6 to 12 feet in diameter.

C-band satellite transmit lowpower signals, usually in the neighborhoodof eight to sixteen watts only about asmuch as a car tall-light bulb uses. By thetime the satellite signal reaches you .It is

very weak in deed. That is why such alarge dish antenna is necessary to pull thesignal out of the background noise



` Azimuth and elevation arethe two basic coordinatesused to determine eachsatellite¶s position in the sky.The azimuth coordinaterepresents the bearing of the satellite from your location. While elevation isthe angle at which the dishlook up at the bird. Everysatellite within view of aspecific installation has itson unique pair of azimuthand elevation coordinates.Given the satellite latitude

and longitude the azimuthand elevation coordinatesfor any satellite are fairlysimple to calculate.



` EIRP-Effective IsotropicRadiated power

EIRP is the power level

from the satellite for aparticular geographiclocation/footprint. It ishigh at the centre of thefootprint and graduallyweakens towards theedge. The unit of EIRPis dBw.



` Every satellite serving the asian region hasseveral channel, called transponders, thatprocess communication traffic. A satellite canhave 24 or more transponders in operation, eachcapable of transmitting one T.V. signal or thousands of simultaneous telephoneconversations. Radio networks are also presenton many transponders, as well as teletext newscomputer information service and other data

transmission.Every transponder¶s signal is also

polarized. Signals of opposite polarization arereceived separately at the receiving station.Polarization allows more channels to fit into thelimited range of frequencies allocated for thesatellites. Many satellites have 12 horizontal and12 vertical transponders which overlap eachother without causing interference.

Satellite transponders operateon frequencies high above those used by theregular TV channels.



` ANTENNA:- A parabolic

structure which collectsmicrowave signals beamedfrom the satellite and focusesthe same onto LNB.

LNB:-RECEIVES & amplifies

microwave signals from theantenna & down converts to I.F.frequency range 950 to1450MHz.

CABLE:-

75 ohms coaxialcable is used to carry the I.F.signal from LNB to the satellitereceiver (RG 11 fromCommscope or Trilogy)



` Antennas used

are parabolicdish antennas.

FOCUS

Geometry of parabolic dish

antenna

Why parabolic AntennaIf flat antenna is used then theIncident ray and Reflected raysAre parallel to each other.

But if parabolic surface is usedThen all the reflected rays areMeet at a point( LNB whichcollect all the signal andprocess it)



The less the F/D, the deeperthe dish,

the lower the gain and the greater therejection of unwanted signal

The choice of satellite dish can assist inrejecting terrestrial interference in that

thedeeper the dish the more narrow willbe

its acceptance of satellite signals andthe

less chance unwanted signals will enterthe

feed assembly.

The deeper the dish and the largerthe

dish, the narrower is the centralreception

beam pattern



` Device on the frontof a satellite dishthat receives thevery low levelmicrowave signalfrom the satellite,

amplifies it, changesthe signals to a lowerfrequency band andsends them down thecable to the indoorreceiver.

Two types of LNB used are:

Features of C-band LNB:

Input Frequency : 3.4 - 4.2 GHz

Output Frequency : 950 - 1750 MHz

LO Frequency : 5.15 GHz

Features of Ku band LNB:

Input Frequency : 10.7 - 12.75 GHz

Output Frequency : 950 - 2150 MHz

LO Frequency : 9.75 GHz low band

10.6 GHz high band

Noise Figure : 0.8 dB typical



LNB is mounted on feedhorn.

It acts as an wave guidewhichdrives the signal to LNB.



TRANSPONDER

An automatic device that receives,

amplifies, and retransmits a signal on adifferent frequency

DOWNLINK

Retransmission of the information from thesatellite back to the ground



UPLINK AND DOWNLINK

Transponder Transponder



` 1)High power is required to penetrate the atmosphere and toovercome free-space spreading loss and other disturbancescaused by the atmosphere....and high power can be achieved if the frequency is increased 2)Also earth station must have highdirectivity i.e narrow bandwidth....narrow bandwidth is directlyproportional to wavelength....lesser the wavelength higher the

frequency... 3)also high power requirement involves the need for high power amplifiers which will increase the weight and power supply ratings of the equipment.since earth station is huge,increase in weight does not has any effect.But since satellite issmall increase in weight requires high power consumption whichcannot be afforded and can results in avoidable

inefficiency................. and hence uplink frequency is greater thandownlink frequency



THANKYOU!

Presentation on t.v. Broadcasting

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