KONGU ENGINEERING COLLEGE

PERUNDURAI, ERODE-38052

TAMIL NADU.

WORKING AND APPLICATION OF

INTERNET PROTOCOL TELEVISION

(IPTV)(IPTV)

SUBMITTED BY

M.Kasthuri (B-Tech – IT IV year) I.Elavarasi (B-Tech – IT IV year)

Mail us:mkasthuri@gmail.comielavarasi@gmail.com

DEPARTMENT OF INFORMATION TECHNOLOGY

KONGU ENGINEERING COLLEGEPERUNDURAI, ERODE-638052

TAMIL NADU

ABSTRACT

In this paper we are going to discuss about an emerging

technology known as Internet Protocol Television (IPTV). Over

the last decade, the growth of satellite service, the rise of digital

cable, and the birth of HDTV have all left their mark on the

television landscape. Now, a new delivery method threatens to

shake things up even more powerfully. Internet Protocol

Television (IPTV) has arrived, and backed by the deep pockets of

the telecommunications industry, it's poised to offer more

interactivity and bring a hefty dose of competition to the business

of selling TV. IPTV describes a system capable of receiving and

displaying a video stream encoded as a series of Internet Protocol

packets. It is used to deliver data, voice and video through single

means of communication known as ‘triple play’. Companies that

offer the triple play want to become your household's sole

communications link, and IPTV is a major part of that strange.

CONTENTS:

WHAT IS IPTV? – AN INTRODUCTION

ARCHITECTURE OF IPTV

HOW IT WORKS?

ADVANTAGES

INTERACTIVITY

VOD

BETTER COMPRESSION

TRIPLE PLAY

IPTV BASED CONVERGED SERVICES

CONCLUSION

FUTURE WORKS

WHAT IS IPTV?

IPTV (Internet Protocol Television) describes a system where a digital

television service is delivered using the Internet Protocol over a network infrastructure,

which may include delivery by a broadband connection. For residential users, IPTV is

often provided in conjunction with Video on Demand and may be bundled with Internet

services such as Web access and VoIP.

While discussing about traditional channels, people demand a smooth, high-

resolution, lag-free picture, and IPTV satisfies their expectations .It's the telcos that are

jumping headfirst into this market. Once known only as phone companies, the telcos 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.

Figure 1 – IPTV brings digital TV, VoD, Internet access, media servingand many other services together for easy access throughout the home.

Architecture

IPTV has two major architecture forms: free and fee based. As of June2006, there

are over 1,300 free IPTV channels available. This sector is growing rapidly and major

television broadcasters worldwide are transmitting their broadcast signal over the

Internet. These free IPTV channels require only an Internet connection and an Internet

enabled device such as a personal computer, iPod, HDTV connected to a computer or

even a 3G cell/mobile phone to watch the IPTV broadcasts. See also: Internet television

Mobile TV

In December 2005, independently produced mariposaHD became the first original

IPTV broadcast available in an HDTV format. Various Web portals offer access to these

free IPTV channels. Some cite the ad-sponsored availability of TV series such as Lost

and Desperate Housewives as indicators that IPTV will become more prevalent.

Because IPTV uses standard networking protocols, it promises lower costs for operators

and lower prices for users. Using set-top boxes with broadband Internet connections,

video can be streamed to households more efficiently than current coaxial cable. ISPs are

upgrading their networks to bring higher speeds and to allow multiple High Definition

TV channels.

Figure2 :IPTV System Architecture

PROTOCOLS

What are all required for building an IPTV? The venerable set-top box, on its way

out in the cable world, will make resurgence in IPTV systems. The box will connect to

the home DSL line and is responsible for reassembling the packets into a coherent video

stream and then decoding the contents. Your computer could do the same job, but most

people still don't have an ‘always-on’ PC sitting beside the TV, so the box will make a

comeback.

IPTV covers both live TV (multicasting) as well as stored video (Video on

Demand VOD). The playback of IPTV requires either a personal computer or a "set-top

box" connected to a TV. Video content is typically an MPEG2 or MPEG4 Transport

stream delivered via IP Multicast in case of live TV or via IP Unicast in case of Video on

Demand. IP Multicast is a method in which information can be sent to multiple

computers at the same time. The newly released (MPEG4) H.264 codec is increasingly

used to replace the older MPEG2.

In standards-based IPTV systems, the primary underlying protocols used for:

Live TV is IGMP version 2 for connecting to a multicast stream (TV channel) and for

changing from one multicast stream to another (TV channel change).VOD is RTSP.

Currently, the only alternatives to IPTV are traditional TV distribution technologies such

as terrestrial, satellite and cable. However, cable can be upgraded to two-way capability

and can thus also carry IPTV.

HOW IT WORKS

Now the setup is over. Where will the box pull its picture from? To answer that

question, let's start at the source.

Most video enters the system at the Telco’s national head end, where network

feeds are pulled from satellites and encoded if necessary (often in MPEG-2, though

H.264 and Windows Media are also possibilities). The video stream is broken up into IP

packets and dumped into the Telco’s core network, which is a massive IP network that

handles all sorts of other traffic (data, voice, etc.) in addition to the video. Here the

advantages of owning the entire network from stem to stern (as the telcos do) really come

into play, since quality of service (QoS) tools can prioritize the video traffic to prevent

delay or fragmentation of the signal. Without control of the network, this would be dicey,

since QoS requests are not often recognized between operators. With end-to-end control,

the telcos can guarantee enough bandwidth for their signal at all times, which is key to

providing the "just works" reliability consumers have come to expect from their

television sets.

The video streams are received by a local office, which has the job of getting

them out to the folks on the couch. This office is the place that local content (such as TV

stations, advertising, and video on demand) is added to the mix, but it's also the spot

where the IPTV middleware is housed. This software stack handles user authentication,

channel change requests, billing, VoD requests, etc.—basically, all of the boring but

necessary infrastructure.

All the channels in the lineup are multicast from the national headend to local

offices at the same time, but at the local office, a bottleneck becomes apparent. That

bottleneck is the local DSL loop, which has nowhere near the capacity to stream all of the

channels at once. Cable systems can do this, since their bandwidth can be in the

neighborhood of 4.5Gbps, but even the newest ADSL2+ technology tops out at around

25Mbps (and this speed drops quickly as distance from the DSLAM [DSL Access

Multiplier] grows).

So how do you send hundreds of channels out to an IPTV subscriber with a DSL

line? Simple: you only send a few at a time. When a user changes the channel on their

set-top box, the box does not "tune" a channel like a cable system. (There is in fact no

such thing as "tuning" anymore—the box is simply an IP receiver.) What happens instead

is that the box switches channels by using the IP Group Membership Protocol (IGMP) v2

to join a new multicast group. When the local office receives this request, it checks to

make sure that the user is authorized to view the new channel, then directs the routers in

the local office to add that particular user to the channel's distribution list. In this way,

only signals that are currently being watched are actually being sent from the local office

to the DSLAM and on to the user.

No matter how well-designed a network may be or how rigorous its QoS controls are,

there is always the possibility of errors creeping into the video stream. For unicast

streams, this is less of an issue; the set-top box can simply request that the server

resend lost or corrupted packets. With multicast streams, it is much more important to

ensure that the network is well-engineered from beginning to end, as the user's set-top

box only subscribes to the stream—it can make no requests for additional

information. To overcome this problem, multicast streams incorporate a variety of

error correction measures such as forward error correction (FEC), in which redundant

packets are transmitted as part of the stream. Again, this is a case where owning the

entire network is important since it allows a company to do everything in its power to

guarantee the safe delivery of streams from one end of the network to the other

without relying on third parties or the public Internet.

Though multicast technology provides the answer to the problem of pumping the

same content out to millions of subscribers at the same time, it does not help with

features such as video on demand, which require a unique stream to the user's home. To

support VoD and other services, the local office can also generate a unicast stream that

targets a particular home and draws from the content on the local VoD server. This

stream is typically controlled by the Real Time Streaming Protocol (RTSP), which

enables DVD-style control over a multimedia stream and allows users to play, pause, and

stop the program they are watching.

The actual number of simultaneous video streams sent from the local office to the

consumer varies by network, but is rarely more than four. The reason is bandwidth. A

Windows Media-encoded stream, for instance, takes up 1.0 to 1.5Mbps for SDTV, which

is no problem; ten channels could be sent at once with bandwidth left over for voice and

data. But when HDTV enters the picture, it's a different story, and the 20-25Mbps

capacity of the line gets eaten up fast. At 1080i, HDTV bit rates using Windows Media

are in the 7 to 8 Mbps range (rates for H.264 are similar). A quick calculation tells you

that a couple of channels are all that can be supported.

The bandwidth situation is even worse when you consider MPEG-2, which has

lower compression ratios. MPEG-2 streams will require almost twice the space (3.5 Mbps

for SDTV, 18-20 Mbps for HDTV), and the increased compression found in the newer

codecs is one reason that AT&T will not use MPEG-2 in the rollout of its IPTV service

dubbed "U-verse."

Simultaneous delivery of channels is necessary to keep IPTV competitive with

cable. Obviously, multiple streams are needed to support picture-in-picture, but they're

also needed by DVRs, which can record one show while a user is watching another. For

IPTV to become a viable whole-house solution, it will also need to support enough

simultaneous channels to allow televisions in different rooms to display different content,

and juggling resulting bandwidth issues is one of the trickiest parts of implementing an

IPTV network that will be attractive to consumers

ADVANTAGES

The IP-based platform offers significant advantages, including the ability to

integrate television with other IP-based services like high speed Internet access and VoIP.

A switched IP network also allows for the delivery of significantly more content and

functionality. In a typical TV or satellite network, using broadcast video technology, all

the content constantly flows downstream to each customer, and the customer switches the

content at the set-top box. The customer can select from as many choices as the cable or

satellite company can stuff into the “pipe” flowing into the home.

A switched IP network works differently. Content remains in the network, and

only the content the customer selects is sent into the customer’s home. That frees up

bandwidth, and the customer’s choice is not limited by the size of the “pipe” into the

home.

Other advantages may include an interactive program guide that allows viewers to

search for content by title or an actor’s name, picture-in-picture functionality that allows

them to “channel surf” without leaving the program they’re watching, and fast channel

changing that eliminates the delay experienced with other digital broadcast services.

Interactivity

An IP-based platform also allows significant opportunities to make the TV

viewing experience more interactive and personalized. For example, viewers may be able

to look up a player’s stats while watching a game, or control the camera angle for a big

play. They also may be able to access photos or music from their PC on their television,

or even use a wireless phone to schedule a recording of their favorite show, or adjust

parental controls so their child can watch a documentary for a school report, while

they’re away from home.

VoD

VoD stands for Video on Demand. VoD permits a customer to browse an online

movie catalogue, to watch trailers and to select the movie he wants to watch. The playout

of the selected movie starts nearly instantaneously on the customer's TV or PC.

Technically, when the customer selects the movie, a point-to-point unicast connection is

set up between the customer's decoder (SetTopBox or PC) and the delivering streaming

server. The signalling for the trick play funcionalities (pause, wind/rewind etc.) is assured

by RTSP (Real Time Streaming Protocol).

The most common codecs used for VoD are MPEG-2, MPEG-4 and VC-1.

In order to avoid content piracy, the VoD content (the movies) is generally encrypted.

Better compression

IPTV uses a more efficient compression standard than FTA digital television,

resulting in smaller file sizes or higher quality TV.

Triple Play

Traditionally, TV has come down one wire (cable TV), the telephone has used

another (the "Plain Old Telephone System"), and the Internet has been available on

either. Both cable operators and telcos operators are starting to offer all three on one wire,

which is more cost effective. Triple play is an expression used by service operators

describing a bundle of telephony, data and video down a single connection.

Triple play does not require that the phone and TV use the Internet Protocol

(Voice over IP & IPTV respectively) - most still offer phone in an analog form. However,

TV over phone connections almost always uses a form of IPTV, which is more

compatible with DSL technologies.

Quad play refers to the triple play package AND mobile telephony - though this is

a package of products rather than sharing a single wire.

IPTV based Converged Services

Another advantage of an IP-based network is the opportunity for integration and

convergence. Converged services imply interaction of existing services in a seamless

manner to create new value added services. One good example is On-Screen Caller ID,

getting Caller ID on your TV and ability to handle it (send it to voice mail, etc). IP-based

services will help to enable efforts to provide consumers anytime, anywhere access to

content over their televisions, PCs and cell phones, and to integrate services and content

to tie them together. Within institutions, IPTV eliminates the need to run a parallel

infrastructure to deliver live and stored video services.

CONCLUSION

IPTV can deliver dozens of channels of video programming through a

relatively low-speed broadband connection (2.2 megabits per second). The advantages of

IP TV include two-way Communication to/from the subscriber, and individual

connections with the capability to deliver customized, rich set of content to individual

subscriber. The video offerings will impose substantial increase in bandwidth needs on

the current access network. The telecom service provider is again faced with optical

technology options while evolving the transport network to accommodate these new high

bandwidth video services.

FUTURE WORK

IPTV transmission should aim in Broadband wireless access (BWA) environment

with high data rates. QoS for video and voice services at reasonable network loads. In

future the performance under variation of the proportions of voice, video and data traffic

loads, delivery of voice and video traffic to the same node.