05b Chapter 02 an Introduction to IPTV Development of IPTV (Smart TV PTCL)

Development of IPTV An Introduction to IPTVPTCL Smart TV

2.1 An introduction to IPTV

Ever wondered how TV over IP works? As AT&T continues to build

out its fiber network, IPTV will become an alternative to traditional cable

and satellite delivery methods. Here's your chance to learn how it works

and what's in the big fiber rollout for you.

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

television service is delivered using Internet Protocol over a network

infrastructure, which may include delivery by a broadband connection. A

general definition of IPTV is television content that, instead of being

delivered through traditional broadcast and cable formats, is received by

the viewer through the technologies used for computer networks.

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. The commercial bundling of IPTV, VoIP and Internet

access is referred to as "Triple Play" service (when these three are offered

with mobility, the service is referred to as "Quadruple Play"). IPTV is

typically supplied by a service provider using a closed network

infrastructure. This closed network approach is in competition with the

delivery of TV content over the public Internet, called Internet Television. In

businesses, IPTV may be used to deliver television content over corporate

LANs.

2.2 Television is changing

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

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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. If you've

ever watched a video clip on your computer, you've used an IPTV system

in its broadest sense. When most people discuss IPTV, though, they're

talking about watching traditional channels on your television, where

people demand a smooth, high-resolution, lag-free picture, and 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.

In this primer, we'll 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, including cable systems, we'll focus in this article

on the telcos, which are the most aggressive players in the game. They're

pumping billions into new fiber rollouts and backend infrastructure (AT&T

alone inked a US$400 million deal for Microsoft's IPTV Edition software

last year, for instance, and a US$1.7 billion deal with hardware maker

Alcatel). Why the sudden enthusiasm for the TV business? Because the

telcos see that the stakes are far higher than just some television:

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

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

2.3 History of IPTV

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IPTV is a system used to deliver digital television services to the

consumers who are registered subscribers for this system. This delivery of

digital television is made possible by using Internet Protocol over a

broadband connection, usually in a managed network rather than the

public Internet to preserve quality of service guarantees. Often, this service

is provided together with Video facility on demand. In addition to this, there

is provision to include Internet services such as web access and Voice

over Internet Protocol (VoIP). In cases when Internet service is also

provided, then it is known as Triple Play.

IPTV uses a Internet Protocol over broadband connection and very

often this service has been provided in parallel with the Internet connection

of the subscriber, supplied by an operator dealing with broadband. This is

done by using the same infrastructure but apparently over a dedicated

bandwidth allocation. Hence, it can be described as a system in which a

digital television service is provided to subscribing consumers over a

broadband connection using the Internet Protocol.

The history of IPTV states that, IPTV is basically a fusion of voice,

video, and data service. It is not a new idea or, rather, development, but it

is a result of high bandwidth and high speed Internet access. In earlier

days, the speed of the Internet did not suit the concept and, as a result, it

affected the voice and video services. In recent times, the speed of Internet

and bandwidth has increased considerably, making IPTV prevail and

become reasonably successful. Also, first generation Set Top Boxes were

prohibitively expensive. The technology costs now permit a viable business

model.

According to the history of IPTV, the year 1994, ABC's World News

was the first television show to be broadcasted over the Internet, using the

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CU-See Me videoconferencing software. The term IPTV first appeared in

1995 with the founding of Precept Software by Judith Estrin and Bill

Carrico. Precept designed and built an Internet video product named

"IPTV". It was an MBONE compatible Windows and Unix based application

that moved single and multi-source audio or video traffic, ranging from low

to DVD quality, using both unicast and IP multicast RTP/RTCP. The

software was written primarily by Steve Casner, Karl Auerbach, and Cha

Chee Kuan. Precept was overtaken by Cisco Systems in 1998. Cisco

retains the "IPTV" trademark.

Internet radio company Audio Net started the first continuous live

web casts with content from WFAA-TV in January, 1998 and KCTU-LP on

January 10, 1998.Kingston Communications, a regional

telecommunications operator in UK, launched KIT that is Kingston

Interactive Television, an IPTV over DSL broadband interactive TV service

in September 1999 after conducting various TV and VoD trials. The

operator added additional VoD service in October 2001 with Yes TV, a

provider VoD content. Kingston was one of the first companies in the world

to introduce IPTV and IP VOD over ADSL as stated by the history of IPTV.

India's state-owned communications services provider, Mahanagar

Telephone Nigam Ltd. (MTNL) will reportedly offer Internet Protocol TV

services (IPTV) under the Tri-Band name, with trial services to soon start

pilot runs in New Delhi and Mumbai. India currently has no policy for IPTV

services, though the Telecom Regulatory Authority of India has floated a

consultation paper and proposed an amendment to the country's Cable TV

Act to govern it.

If not today, then sometime soon, as per the history of IPTV, it will

become a big business. The incumbent telecom operators worldwide are

investing heavily in IPTV business. Infonetics Research, a Campbell,

California based research firm forecasts that there will be 68.9 million IPTV

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subscribers by 2009.Countries like India and China, which have little or

poor cable infrastructure are embracing IPTV, and so are European Union

members. So far, the big growth in subscribers and revenues is coming

overseas, especially in Europe.

2.4 IPTV Regulation

Historically Broadcast TV has been regulated differently than

Telecom and Internet. As IPTV allows TV and VOD to be transmitted over

IP networks new regulatory issues arise. Professor Eli M. Noam, highlights

in his report " TV or Not TV: Three Screens, One Regulation?" some of the

key challanges with sector specific regulation that is becomming obsolate

due to convergence in this field. To find out more about the issues go to

the Canadian Regulator and check out the report.

2.5 Definition

It is important to note that historically there have been many

different definitions of "IPTV" including elementary streams over IP

networks, transport streams over IP networks and a number of proprietary

systems. Although (in Mid 2007) it is premature to say that there is a full

consensus of exactly what IPTV should mean, there is no doubt that the

most widely used definition today is for single or multiple program transport

streams (MPTS) which are sourced by the same network operator that

owns or directly controls the "Final Mile" to the consumer's premises. This

control over delivery enables a guaranteed quality of service, and also

allows the service provider to offer an enhanced user experience such as

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better program guide, interactive services etc.

The official definition approved by the International

Telecommunication Union focus group on IPTV (ITU-T FG IPTV) is as

follows:

"IPTV is defined as multimedia services such as

television/video/audio/text/graphics/data delivered over IP

based networks managed to provide the required level of

quality of service and experience, security, interactivity and

reliability."

2.6 Markets

While all major western countries and most developed economies

have IPTV deployments, the world's leading markets for IPTV for now are

France (led by Free, then Orange, then Neuf Cegetel; total of over 4 million

subscriptions), South Korea (1.8 million subscriptions), Hong Kong, Japan,

Italy, Spain, Belgium, China, Switzerland and Portugal. Services have also

launched in Slovenia, Croatia, Serbia, Montenegro, Scandinavia and, with

two competing players, Iceland. The United Kingdom launched IPTV early

but has been slow to grow. IPTV is just beginning to grow in Central and

Eastern Europe,now it is growing in South Asian countries such as Sri

Lanka, Pakistan and especially India.[8] but significant plans exist in

countries such as Poland and Russia.

The first IPTV service to launch on the Chinese mainland sells

under the "BesTV" brand and is currently available in the cities of Shanghai

and Harbin.

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2.7 IPTV and Internet TV

A telco IPTV service is usually delivered over a complex and

investment heavy walled garden network, which is carefully engineered to

ensure bandwidth efficient delivery of vast amounts of multicast video

traffic. The higher network quality also enables easy delivery of high quality

SD or HD TV content to subscribers’ homes. This makes IPTV by default

the preferred delivery platform for premium content. However the

investment for a telco to build an end-to-end IPTV service can be

substantial.

By contrast "Internet TV" generally refers to transport streams sent

over IP networks (normally the Internet) from outside the network that

connects to the users premises. An Internet TV provider has no control

over the final delivery and so broadcasts on a "best effort" basis.

Elementary streams over IP networks and proprietary variants as used by

websites such as YouTube are now rarely considered to be IPTV services.

Compared to telco IPTV, Internet TV is a quick-to-market and

relatively low investment service. Internet TV rides on existing

infrastructure including broadband, ADSL, Wi-Fi, cable and satellite which

makes it a valuable tool for a wide variety of service providers and content

owners looking for new revenue streams. However, due to the fact that

IPTV is always delivered over low cost IP STBs, which have limited

computing power, the capability for IPTV operators to provide diverse

multimedia services is limited. This is where Internet TV has an advantage

as it is delivered to a subscriber's (generally) powerful PC.

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The relative ease of establishing an Internet TV service seems at

first a threat to telco IPTV operators’ multimillion dollar investment, but both

services do not necessarily compete for the same customers and there are

some synergies between the two such as a common technology platform

in the form of web-based technologies for content storage and delivery.

Broadcast IPTV has two major architecture forms: free and fee

based. As of June 2006, there are over 1,300 free IPTV sources available.

This sector is growing rapidly and major television broadcasters worldwide

are transmitting their broadcast signal over the Internet. These free IPTV

sources require only an Internet connection and an Internet enabled device

such as a personal computer, HDTV connected to a computer or even a

3G cell/mobile phone to watch the IPTV content. Various Web portals offer

access to these free IPTV sources. Some cite the ad-sponsored availability

of TV series such as Lost 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.

IPTV uses a two-way digital broadcast signal sent through a

switched telephone or cable network by way of a broadband connection

and a set-top box programmed with software (much like a cable or DSS

box) that can handle viewer requests to access to many available media

sources.

Local IPTV, as used by businesses for Audio Visual AV distribution

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on their company networks is typically based on a mixture of: a)

Conventional TV reception equipment and IPTV encoders b) IPTV

Gateways that take broadcast MPEG channels and IP wrap them to create

multicast streams.

2.8 How it works

First things first: 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. 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 headend, 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.

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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

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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

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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.

2.9 Time for a triple play

How big will the IPTV market be? Multimedia Research Group

estimates that IPTV subscribers will balloon from 3.7 million in 2005 to 36.9

million by 2009 (worldwide), with Europe leading the market. The industry's

revenues could reach nearly US$10 billion by that time—no small chunk of

change. Still, the battle is for more than just your television; it's a struggle

for the single entry point into your home.

The so-called "triple play" of voice, video, and data is currently a

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holy grail for the telcos, who need to compete with the cable companies,

which already offer all three services. With both telcos and cable providers

offering the triple play, it's likely that consumers will soon need only a

single data pipe flowing into their home (and bundle discounts will ensure

that this is the cheapest way to do things). Whichever pipe that turns out to

be—cable or telephone line—will mean big money for the company that

owns it.

IPTV provides the missing piece that the telcos need, but the cable

companies, for their part, are talking tough. "AT&T is spending years and

billions of dollars to imitate a network that Comcast has already built," said

spokesman Andrew Johnson. "We've seen nothing... that we can't

exceed." Despite the posturing, both industries see this as an important

transition time during which they need to sell customers on the merits of

one-stop shopping for their communication and entertainment needs.

Hopefully, the battle of words will soon give way to the price war that

satellite could not fully spark, in which case IPTV, if it does nothing else,

will have succeeded.

2.10 Protocols

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

compressed using either a MPEG-2 or a MPEG-4 codec and then sent in

an MPEG 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 (MPEG-4) H.264 codec is increasingly used to replace the

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older MPEG-2 codec.

In standards-based IPTV systems, the primary underlying protocols

used are:

Live TV uses IGMP version 2 or IGMP version 3 for IPv4 for

connecting to a multicast stream (TV channel) and for changing

from one multicast stream to another (TV channel change).

VOD is using the Real Time Streaming Protocol (RTSP).

N-PVR (Network-based Personal Video Recorder) is also using the

Real Time Streaming Protocol (RTSP).

Network Personal Video Recording is a consumer service where

real-time broadcast television is captured in the network on a server

allowing the end user to access the recorded programs on the schedule of

their choice, rather than being tied to the broadcast schedule. The NPVR

system provides time-shifted viewing of broadcast programs, allowing

subscribers to record and watch programs at their convenience, without the

requirement of a truly personal PVR device. It could be compared as a

"PVR that is built into the network" -- however that would be slightly

misleading unless the word "Personal" is, of course, changed to "Public"

for this context.

Subscribers can choose from the programmes available in the

network-based library, when they want, without needing yet another device

or remote control. However, many people would still prefer to have their

own PVR device, as it would allow them to choose exactly what they want

to record. This bypasses the strict copyright and licensing regulations, as

well as other limitations, that often prevent the network itself from providing

"on demand" access to certain programmes (see Heroes, below).

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In Greece, On Telecoms offers an NPVR service to all subscribers

in their basic package with all the programming of all major national Greek

TV channels for the last 72 hours. The user has to sign in their contract

that they agree that the company will record national programming of the

last 72 hours FOR them so that they can come around any legal

implications (like the ones mentioned here) as this service would work like

a personal PVR.

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.

2.11 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 telecomms, 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 less restricted by the size of

the “pipe” into the home. This also implies that the customer's privacy

could be compromised to a greater extent than is possible with traditional

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TV or satellite networks. It may also provide a means to hack into, or at

least disrupt (see Denial of Service) the private network.

Interactivity

An IP-based platform also allows significant opportunities to make

the TV viewing experience more interactive and personalized. The supplier

may, for example, include an interactive program guide that allows viewers

to search for content by title or actor’s name, or a picture-in-picture

functionality that allows them to “channel surf” without leaving the program

they’re watching. Viewers may be able to look up a player’s stats while

watching a sports game, or control the camera angle. They also may be

able to access photos or music from their PC on their television, use a

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

adjust parental controls so their child can watch a documentary for a

school report, while they’re away from home.

Note that this is all possible, to some degree, with existing digital

terrestrial, satellite and cable networks in tandem with modern set top

boxes. In order that there can take place an interaction between the

receiver and the transmitter a feedback channel is needed. Due to this

terrestrial, satellite and cable networks for television does not allow

interactivity. However, interactivity with those networks can be possible in

the combination with different networks like internet or a mobile

communication network.

VoD

VoD stands for Video on Demand. VoD permits a customer to

browse an online programme or film catalogue, to watch trailers and to

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then select a selected recording for playback. 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

functionality (pause, slow-motion, 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 an attempt to avoid content piracy, the VoD content is usually

encrypted. Whilst encryption of satellite and cable TV broadcasts is an old

practice, with IPTV technology it can effectively be thought of as a form of

Digital Rights Management. A film that is chosen, for example, may be

playable for 24 hours following payment, after which time it becomes

unavailable.

IPTV based Converged Services

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

integration and convergence. This opportunity is amplified when using IMS-

based solutions. Converged services implies 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 the

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 (for example see

http://www.ericsson.com/campaign/televisionary/), and to integrate

services and content to tie them together. Within businesses and

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institutions, IPTV eliminates the need to run a parallel infrastructure to

deliver live and stored video services.

2.12 Limitations

IPTV is sensitive to packet loss and delays if the streamed data is

unreliable. IPTV has strict minimum speed requirements in order to

facilitate the right number of frames per second to deliver moving pictures.

This means that the limited connection speed/bandwidth available for a

large IPTV customer base can reduce the service quality delivered.

Although a few countries have very high speed broadband-enabled

populations, such as South Korea with 6 million homes benefiting from a

minimum connection speed of 100Mbps, in other countries (such as the

UK) legacy networks struggle to provide 3-5Mbps and so simultaneous

provision to the home of TV channels, VOIP and Internet access may not

be viable. The last mile delivery for IPTV usually has a bandwidth

restriction that only allows a small number of TV channels – typically from

one to three – to be delivered.

The same problem has also proved troublesome when attempting to

stream IPTV across wireless links within the home. Improvements in

wireless technology are now starting to provide equipment to solve the

problem.

Latency

The latency inherent in the use of satellite internet is often held up

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as reason why satellites cannot be successfully used for IPTV, but in

practice latency is not an important factor for IPTV. An IPTV service does

not require real-time transmission, as is the case with telephony or

videoconferencing services.

It is the latency of response to requests to change channel, display

an EPG, etc that most affects customers’ perceived quality of service, and

these problems affect satellite IPTV no more than terrestrial IPTV. Indeed,

command latency problems, faced by terrestrial IPTV networks with

insufficient bandwidth as their customer base grows, may be solved by the

high capacity of satellite distribution.

Satellite distribution does suffer from latency – the time for the signal

to travel up from the hub to the satellite and back down to the user is

around 0.25 seconds, and cannot be reduced. However, the effects of this

delay are mitigated in real-life systems using data compression, TCP-

acceleration, and HTTP pre-fetching.

Satellite latency can be detrimental to especially time-sensitive

applications such as on-line gaming (although it only seriously affects the

likes of first-person shooters while many MMOGs can operate well over

satellite internet), but IPTV is typically a simplex operation (one-way

transmission) and latency is not a critical factor for video transmission.

Existing video transmission systems of both analogue and digital

formats already introduce known quantifiable delays. Indeed, existing DVB

TV channels that simulcast by both terrestrial and satellite transmissions,

experience the same 0.25s delay difference between the two services with

no detrimental effect, and it goes unnoticed by viewers.

Privacy implications

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AS IPTv is a two way protocol the ISP knows which program is

being watched.

2.13 Vendors

A small number of companies supply most current IPTV systems.

Some, such as Imagenio, were formed by telecoms operators themselves,

to minimise external costs, a tactic also used by PCCW of Hong Kong.

Some major telecoms vendors are also active in this space, notably

Huawei of China (IPTV Solution) Alcatel-Lucent (sometimes working with

Imagenio), Ericsson (notably since acquiring Tandberg Television), NEC,

Thomson, Logic Innovations, and ZTE, as are some IT houses, led by

Microsoft. California-based UTStarcom, Inc., Tennessee-based Worley

Consulting and Tokyo-based The New Media Group also offer end-to-end

networking infrastructure for IPTV-based services, and Hong Kong-based

BNS Ltd. provides turnkey open platform IPTV technology solutions. Global

sales of IPTV systems exceeded 2 billion USD in 2007.

Many of these IPTV solution vendors participated in the biennial

Global MSF Interoperability 2008 (GMI) event which was coordinated by

the MultiService Forum (MSF) at five sites worldwide from 20- to 31-

October 2008. Test equipment vendors including Empirix, Ixia, Mu

Dynamics and Spirent joined solution vendors such as the companies

listed above in one of the largest IPTV proving grounds ever deployed.