report on communication medium in modern tv

120970107021 Communication mediums in modern TV

Marwadi Education Foundation i

Abstract

No other electronic media has created as much mass impact as the TV.TV is both a personal as well as

family/community device which makes it reach a large population. Obviously the immense popularity of TV

has resulted in an unprecedented growth of TV viewing as well as technology. From the simple TV, today one

can have a smart TV with varying features satisfying all sections of society. Not only have the TV signals

been converted from analog to digital, today one has high definition TV, the IPTV, the dbs TV available. This

gives an overview of the communication mediums in modern TV

With the development in compression techniques and bandwidth efficient modulation techniques digital

transmission has become a reality. Digital TV has removed the line of distinction between the computer and

TV and merged TV and computing because of the digital representation of image and video. Digital TV also

called as Direct Broadcast Satellite (DBS) TV and Direct to Home (DTH) TV. It is broadcasted using satellite

system, where before transmission the signals which may originate from various sources are converted to

digital, compressed, time division multiplexed and modulated before transmitting on uplink to the satellite

transponder. The receiver unit at home of the user has an important device called Digital Set top box which

provides the user the access to various digital content.

IPTV or Internet Protocol Television is a scheme that uses IP networking protocol to transport data. IPTV

differs from terrestrial broadcasting TV as IPTV is interactive that is two way user sends his requests and

based on that receives the services whereas terrestrial broadcasting TV is one way. Management in Terrestrial

broadcasting TV is almost nil whereas IPTV is fully managed including the billing, also the streaming in

terrestrial TV systems is simultaneous whereas in IPTV systems it is in bundles.


Marwadi Education Foundation ii

Acknowledgment

It is needed a great pleasure to express my thanks and gratitude to all those who helped me. No serious and

lasting achievement or success, one can ever achieve without the help of friendly guidance and cooperation of

so many people involved in the report.

I am very thankful to my guide Prof. Hemang Kothari, the person who makes me to follow the right steps

during a seminar work. I express my deep sense of gratitude to for his guidance, suggestions and expertise at

every stage. Apart from that his valuable and expertise suggestion during documentation of my report indeed

help me a lot.

Thanks to my friend and colleague who have been a source of inspiration and motivation that helped to me

during my seminar work. I would heartily thankful to head of our computer department Prof. Jay Teraiya to

give me an opportunity to work over this topic and for their endless and great support. And to all other people

who directly or indirectly supported and help me to fulfill my task.

And at last but not least, I would be grateful towards my parents and friends who had supported a lot and

provided inspiration and motivation to go in this area.

HARSH MEHTA

120970107021


Marwadi Education Foundation iii

Table of Contents

Abstract.............................................................................................................................................................. i

Acknowledgment............................................................................................................................................... ii

List of Figure ......................................................................................................................................................iv

Chapter 1: INTRODUCTION ..................................................................................................................................1

Chapter 2: DIRECT BROADCAST SATELLITE ............................................................................................................2

2.1 What is dbs? ..................................................................................................................................................2

2.2 Components involved in dbs...........................................................................................................................3

2.3 Application ....................................................................................................................................................4

Chapter 3: MULTIPLE ACCESS ...............................................................................................................................5

3.1 FDMA............................................................................................................................................................5

3.2 TDMA............................................................................................................................................................5

3.3 Advantages of TDMA over FDMA: ...................................................................................................................5

3.4 Dama ............................................................................................................................................................6

Chapter 4: VIDEO COMPRESSION .........................................................................................................................8

4.1 MPEG ............................................................................................................................................................8

4.2 MPEG-1 .........................................................................................................................................................8

4.3 MPEG-2 .........................................................................................................................................................8

4.4 MPEG-4 .........................................................................................................................................................8

4.5 Mpeg-2 Video Compression............................................................................................................................8

Chapter 5: IPTV ................................................................................................................................................. 10

5.1 Triple Play Service ........................................................................................................................................ 10

5.2 Triple Play Setup Using ADSL Modem And Splitter ......................................................................................... 10

5.3 Features Does IPTV Offer.............................................................................................................................. 12

5.4 Advantages Of Iptv....................................................................................................................................... 15

5.5 Disadvantages Of Iptv.................................................................................................................................. 15

5.6 Future of Iptv............................................................................................................................................... 15


Marwadi Education Foundation iv

List of Figure

Figure 2.1 Direct broadcast satellites............................................................................................................... 2

Figure 2.2 Components involved in dbs .......................................................................................................... 3

Figure 3.4 Direct broadcast satellite television................................................................................................ 7

Figure 4.5 Mpeg-2 frames ............................................................................................................................... 9

Figure 5.0 Iptv ............................................................................................................................................... 10

Figure 5.2 Triple play setup using ADSL modem and splitter ...................................................................... 11

Figure 5.3 Feature of iptv .............................................................................................................................. 14

Figure 5.6 Future of iptv ................................................................................................................................ 16

List of


Marwadi Education Foundation 1

Chapter 1: INTRODUCTION

Direct broadcast satellite (DBS) and has experienced continual growth in capacity since its beginnings. Its

growth has been enabled by several core technologies, the capabilities of which increase over time. This

looks at DBS services in the globe, examines how system capacity has changed over time, and looks at how

some core technologies will likely evolve. It is found that there is no technical barrier to further capacity

increases being implemented over time in the services.

Video compression uses digital technology to reduce the number of bits needed to send a video program. The

more efficient the video compression technology, the fewer bits needed for each channel, and the more

channels that can be sent using a satellite transponder’s fixed bandwidth. Alternatively, more efficient video

compression allows the same bit rate to be used to send higher-resolution video.

IPTV describes a system capable of receiving and displaying a video stream encoded as a series of Internet

Protocol packets. If you've ever watched a video clip on your computer, you've used an IPTV system in its

broadest sense. Once known only as phone companies, they now want to turn a "triple play" of voice, data,

and video that will retire the side and put them securely in the batter's box. In this explain how IPTV works

and what the future holds for the technology. Though IP can (and will) be used to deliver video over all sorts

of networks.



Chapter 2: DIRECT BROADCAST SATELLITE

2.1 What is dbs?

DBS Satellite used to deliver TV programs to viewers all over the world; Ex “Nile-Sat”.The signals used by

broadcast TV satellites are typically digitally compressed. The provider selects programs and broadcasts

them to subscribers as a set package. DBS technology enables consumers to receive digitally modulated

television signals directly from satellites.

Figure 2.1 Direct broadcast satellites

Direct Broadcast Satellite is a communication link that transmits directly from the transmitter to the user. The

end user receives data from a high frequency satellite in geosynchronous orbit (GEO). The high power of

transmission from this satellite allows the user's receiving dish to be the size very small. By using video

compression and encoding in the transmission, hundreds of channels can be broadcast over the bandwidth

available.



2.2 Components involved in dbs

Figure 2.2 Components Involved In Dbs

Programming sources are simply the channels that provide programming for broadcast. The provider doesn't

create original programming itself. It pays other companies for the right to broadcast their content via

satellite. The broadcast center is the central hub of the system. At the broadcast center, the TV provider

receives signals from various programming sources and beams a broadcast signal to satellites in

geosynchronous orbit. The satellites receive the signals from the broadcast station and rebroadcast them to

Earth. The viewer's dish picks up the signal from the satellite and passes it on to the receiver in the viewer's

house. The receiver processes the signal and passes it on to a standard TV.



2.3 Application

Subscription based TV

Pay per view

Digital video records

Interactive services



Chapter 3: MULTIPLE ACCESS

3.1 FDMA

Frequency division multiple access, as the name suggests, operates by dividing the available bandwidth

between users on the basis of frequency. A group of users may be allotted a range of frequencies and each

individual user can use a limited frequency shifted channels, within that range. Earlier analogue FDMA used

FM waves with slightly different carrier frequencies to get the job done.

A method allowing multiple carriers to share a single satellite transponder or range of frequencies. The

transponder bandwidth is divided into sub-channels, each of which is allocated to a particular earth station

(carrier).The earth stations transmit continuously and the transponder conveys several carriers simultaneously

at different frequencies

FDMA can be performed in two ways:

Fixed-assignment multiple access (FAMA): The sub-channel assignments are of a fixed allotment.

Ideal for broadcast satellite communication.

Demand-assignment multiple access (DAMA): The sub-channel allotment changes based on demand.

Ideal for point to point communication.

3.2 TDMA

In TDMA, ideally, the whole bandwidth is used by a user for a fixed amount of time. All practical TDMA

signals are digital and hence are advantageous over traditional FDMA system. Problems of non-linearity are

not present here as at a time the whole bandwidth of a transponder is used only by a single .However, need

for higher bit rates (requires more energy) and presence of ISI can be a problem.

In Time Division Multiple Access (TDMA), it makes use of the same frequency spectrum but allows more

users on the same band of frequencies by dividing the time into “slots” and shares the channel between users

by assigning them different time slots.TDMA is utilized by Digital-Advanced Mobile Phone System (D-

AMPS) and Global System for Mobile communications (GSM).

However, each of these systems implements TDMA in a somewhat different and incompatible way.

3.3 Advantages of TDMA over FDMA:

Digital equipment used in time division multiplexing is increasingly becoming cheaper.

There are advantages in digital transmission techniques. Ex: error correction



No need for precise narrowband filters.

Easy for mobile or base stations to initiate.

The most cost-effective technology for upgrading a current analog system to digital.

3.4 Dama

This technique is used when the link between the station and satellite is not a constant one. This helps assign

bandwidth according to demand. This can be implemented on TDMA or as a combination with FDMA and

TDMA.

DAMA is often used in military environments due to the relative simplicity of implementation and ease of

modelling. It can operate with bent pipe transponders and thus require no security on the satellite side. The

master and slave stations can upgrade compressions without expensive satellite replacements.Set of sub

channels in a channel is treated as a pool of available links .For full-duplex between two earth stations, a pair

of sub channels is dynamically assigned on demand.Demand assignment performed in a distributed fashion

by earth station using CSC.



Figure 3.4 Direct Broadcast Satellite Television



Chapter 4: VIDEO COMPRESSION

4.1 MPEG

MPEG stands for Moving Picture Coding Exports Group. At the same time it describes a whole family Of

international standards for the compression of audio-visual digital data. The most known are MPEG-1,

MPEG-2 and MPEG-4, which are also formally known as ISO/IEC-11172, ISO/IEC-13818 and ISO/IEC-

14496.

4.2 MPEG-1

Allowed to play a video in real time from a 1x CD-ROM. The frame rate in MPEG-1 is locked at 25 (PAL)

fps and 30 (NTSC) fps respectively. Further MPEG-1 was designed to allow a fast forward and backward

search and a synchronisation of audio and video. A stable behaviour, in cases of data loss, as well as low

computation times for encoding and decoding was reached, which is important for symmetric applications,

like video telephony.

4.3 MPEG-2

Which allowed a higher quality with a slightly higher bandwidth? MPEG-2 is compatible to MPEG-1. Later

it was also used for High Definition Television (HDTV) and DVD, which made the MPEG-3 standard

disappear completely. The frame rate is locked at 25 (PAL) fps and 30 (NTSC) fps respectively, just as in

MPEG-1. MPEG-2 is more scalable than MPEG-1 and is able to play the same video in different resolutions

and frame rates.

4.4 MPEG-4

It provided lower bit rates (10Kb/s to 1Mb/s) with a good quality. It was a major development from MPEG-

2 and was designed for the use in interactive environments, such as multimedia applications and video

communication. It enhances the MPEG family with tools to lower the bit-rate individually for certain

applications. It is therefore more adaptive to the specific area of the video usage.

4.5 Mpeg-2 Video Compression

Video and Audio, and sometimes Data elements are encoded into a sequence of frames. A frame is a single

image from a video or audio sequence. In most countries, one frame occurs every 33 milliseconds. Each

frame is encoded in one of three ways:

1. I – Frame

Compressed directly from a raw (uncompressed) frame.



Compression is based in the current raw frame only and inability of human eye to detect certain

changes in the image.

I-frame is a reference frame and can be used to predict the P-frame immediately following it

2. P – Frame

Compression is based on spatial redundancy (pixels) as well as on time based redundancy (frame).

P-frame can be predicted by referring I-frame or P-frame immediately preceding it.

3. B - Frame

Compression is similar to P-frame except that B-frame compression is done by referring previous as

well as I-frame and P-frame

Figure 4.5 Mpeg-2 Frames



Chapter 5: IPTV

IPTV stands for Internet Protocol Television. It is a digital television services that receives both TV or

multimedia services via Internet connection. IPTV will provide better quality of service than Internet

streaming video.IPTV has the potential to offer an interactive, customized experience.

Figure 5.0 Iptv

5.1 Triple Play Service

Triple Play service is a complete package that allows customers to watch TV, browse the internet and making

a long distance calls using the VoIP. This service is typically provided by a service provider using a closed

network infrastructure. Triple play services require a network that is scalable to deliver these services to the

mass market; reliable, to provide the optimal quality of experience for the subscriber; and flexible, to adapt to

service changes and new service opportunities.

5.2 Triple Play Setup Using ADSL Modem And Splitter

Broadband is an ‘always-on’ high speed internet service. The Broadband service “Triple Play” i.e. Voice,

Video and Data services all possible simultaneously on the same copper telephone line. MTNL is currently

offering Internet Services starting from 256 kbps going up to 2 Mbps. For extending these services the

telephone cable coming to the subscriber’s premises is connected to a Broadband Modem (ADSL2+ modem)

using a POTS Splitter. The Broadband Modem acts as an interface between telephone cable and computer.

The “POTS Splitter” is used to separate voice and data signals enabling both Voice and Internet



simultaneously on the same telephone line. One cable out of POTS Splitter is connected to the telephone

instrument.

Figure 5.2 Triple Play Setup Using ADSL Modem And Splitter

Broadband is an ‘always-on’ high speed internet service. The Broadband service “Triple Play” i.e. Voice,

Video and Data services all possible simultaneously on the same copper telephone line. MTNL is currently

offering Internet Services starting from 256 kbps going up to 2 Mbps. For extending these services the

telephone cable coming to the subscriber’s premises is connected to a Broadband Modem (ADSL2+ modem)

using a POTS Splitter. The Broadband Modem acts as an interface between telephone cable and computer.

The “POTS Splitter” is used to separate voice and data signals enabling both Voice and Internet

simultaneously on the same telephone line. One cable out of POTS Splitter is connected to the telephone

instrument.



The POT's splitter should be placed at a suitable point before any other device is connected to the telephone

line. This is important for proper working of the Broadband connection. The POT's splitter has three ports

which are to be connected as below –

Line port – for connecting the telephone line from exchange.

Phone port – for connecting the telephone instrument.

DSL port for connecting the Broadband modem.

The interfaces are to be connected as follows –

ADSL interface (RJ 11) for connecting the incoming DSL line from the POTS splitter.

Ethernet interface (RJ45) for connecting the Ethernet cable from the PC.

USB interface for connecting the USB cable from the PC.

5.3 Features Does IPTV Offer

1. Broadcast type

Pay TV

Electronic Programmed Guide (EPG)

Live Streaming for VOD

Progressive Downloads(Video, gaming, music downloads)

2. Interactive type

Interactive TV

Video Conferencing

Interactive Online Network Gaming

Interactive E-Learning

3. On Demand type

Interactive VOD(video on demand)

Client side Personal Video Recording

Pay per View(PPV)

Time Shifted TV



4. Internet and Voice types

VoIP

Browsing on TV

E-mail/SMS/MMS from TV

Caller ID Popup



Figure 5.3 Features of Iptv



5.4 Advantages Of Iptv

Other than wireless communication, another advantage of IPTV is that if the customer has quadruple play

(internet television, telephone, mobile phone service) with the same company, the cell phone can be used to

schedule the recording of a program. Excluding cell phone service and having only three services with a

company is referred to as triple play

5.5 Disadvantages Of Iptv

There are some limitations to IPTV. According to Wikipedia, because IPTV is based on the Internet Protocol,

it is sensitive to packet loss and delays if the IPTV connection is not fast enough and it also does not support

HDTV at the moment. AT&T is currently experimenting with HDTV and its U-Verse service in the Houston

area according to Cable Industry Insider.

5.6 Future of Iptv

IPTV is much different than the digital video accessed by millions of users on YouTube or other video

streaming websites, but it shares a lot of the same ubiquitous, pervasive nature. A single subscription can be

accessed by multiple television sets within a home, and Internet-based transmission allows for web-based

applications to enhance a viewer’s experience. Our goal today is to explore the the current state of IPTV and

Internet television technologies globally, as well as what the near future holds for these entertainment

systems.

With these new companies in the mix, competition for television subscribers will likely heat up in the coming

years. Companies’ currently offering web and television services could likely be enticed to open up their

regional basis and begin competing for customers across the country. Telecom companies that develop their

own IPTV services may be able to keep the complete price of their Internet and television bundle down the

most, but unless they offer both a wide selection and large degree of customization, but Internet-based

streaming services like Netflix, Hulu+ and Amazon Prime already enjoy a great number of customers without

providing Internet.



Figure 5.6 Future Of Iptv

The idea of the “second screen” is a recent concept growing quickly due to the development of IPTV

technologies. Customers will likely begin accessing broadcasted content through tablets and other Internet-

connected mobile electronic devices. These services will allow users to access video-on-demand and other

broadcast services through a device while outside of the home.



References:

1. Timothy Pratt, Charles bostian and Jeremy allnut, “satellite communications", john Wiley & sons, Inc.,

second edition, 2006.

2. http://en.wikipedia.org/wiki/direct-broadcast_satellite

3. http://www.maplenet.net/~trowbridge/dbsintro.htm

4. http://www.bretl.com/mpeghtml/mpegindex.htm

5. Directbroadcastsatellitetv-090723111626-phpapp02.slideshare

6. Directbroadcastsatellitetv-090723111626-phpapp02.slideshare

7. Iptv-121106124704-phpapp02.pptx.slideshare

8. Tiberius Artzi, “direct satellite communication", us patent no.6553009, issued on April 22, 2003.

report on communication medium in modern tv

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