INTERNET PROTOCOL TELEVISION (IPTV)

I. INTRODUCTION

I.i. Television Is Changing
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. 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 Telco’s that are jumping headfirst into this market. Once known only as phone companies, the Telco’s 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.

I.ii. 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 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 Telco’s 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 Telco’s 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 codec’s 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.


II. SHORT HISTORY of IPTV

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. Technology costs now permit a viable business model.


Figure 1. Process per User Model



                  








III. INTERNET PROTOCOL TELEVISION (IPTV)


III.i. Definition

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. For residential users, this type of service is often provided in conjunction with Video on Demand and may be part of Combined Internet Services such as Web access and VoIP, where it may then be called Triple Play or Quad Play, and is typically supplied by a broadband operator using a single infrastructure. In businesses IPTV may be used to deliver television content over corporate LAN's and business networks.

Perhaps a simpler definition of IPTV would be television content that, instead of being delivered through traditional formats and cabling, is received by the viewer through the technologies used for computer networks. In the past, this technology has been restricted by slow download speeds. In the coming years, however, residential IPTV is expected to grow at a brisk pace as broadband is now available to more than 100 million households worldwide. Many of the world's major telecommunications providers are exploring IPTV as a new revenue opportunity from their existing markets and as a defensive measure against encroachment from more conventional Cable Television services.
Today, IPTV is creating headlines all over the world. This mass publicity is the result of numerous instances and stories depicting its humble deployments and its future. IPTV is a very useful system, through which you can receive both TV and video signals along with other multimedia services by means of your Internet connection. In a nutshell, it is nothing but a broadband connection and a system to deliver various programs of television using the Internet protocol (i.e., language) over computer networks.



III.ii. Overview


It is important to remember that IPTV is not like any ordinary television program broadcast through the Internet, but rather it is unique in itself. Its contour is represented by a closed, proprietary TV system which is similar to the cable services present today. But, in contrast, the delivery of IPTV is made via IP-based secure channels, which result in a sharp increase in content distribution control.

The role of IPTV is to integrate numerous ways to scrutinize and trace choices of users. Its role is also to mark out the preferences and selections over a particular time period. It is therefore emerging as a perfect platform on which clients add personalized e-commerce options and a more targeted advertising. By now, IPTV has turned out to be a widespread denominator for systems where both television and video signals are circulated to subscribers or viewers.

IPTV uses an 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, we can describe it as a system in which a digital television service is provided to subscribing consumers over a broadband connection using the Internet Protocol.

Moreover, one must also remember that IPTV is noticeably different from "Internet Video". Internet Video provides services to watch videos, such as movie previews and web-cams. This service is a so-called "best effort" by providers of Internet, which has no back-to-back service management along with quality of service considerations.

In contrast, IPTV technology is more advanced, user friendly, and incorporated with the higher speed digital subscriber line (DSL) access technologies, such as asymmetric digital subscriber line (ADSL2), ADSL2+ and very-high-data-rate digital subscriber line (VDSL). This certainly offers eye-catching revenue-generating opportunities for the telecom service providers. Therefore, IPTV allows the service providers to participate and to compete efficiently in the so-called "triple play" market space. It is important to note here that the service is very prompt and effective with the delivery of voice, data, and video services to customers who can be both residential and business related.


IV. ARCHITECTURE


IPTV uses the switched digital video architecture. That enables users to customize their viewing by removing the restrictions of channel based Surfing. IPTV sends only one program at a time. When a viewer changes a channel or selects a program, a new stream of content is transmitted from the provider’s server directly to the viewer’s set-top box. The promise of IPTV lies in its switched digital video architecture. IPTV primarily uses multicasting with Internet Group Management Protocol (IGMP) version 2 for Real Time Streaming Protocol for on-demand programs. Compatible video compression standards include H.264, Windows Media Video 9 and VC1, DivX, XviD, Ogg Theora and the MPEG-2and 4.

IPTV allows operators to deliver content to their subscribers using telephone lines through IP technology. So far this technology was being used to deliver voice over internet telephony. The services on IPTV include video-on-demand and digital video recording. 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 that can handle viewer requests to access many available media sources. The viewer’s TV connects to a set-top box that decodes the IP video and converts it into standard television signals. The consumer can access different media by using the television remote to send control commands.

IP television is the transmission of television (digital video and audio) through data networks such as DSL, cable modem or wireless broadband. IP television services may be on a subscription basis (paid for by the recipient) or may be funded by commercials or government agencies. IP television broadcasters transmit multimedia data signals to end users or they can send the media to multicast distribution points that redirect the digital television signals to end user. IPTV has two major architecture forms: free and fee based. As of June 2006, 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 (3ed generation mobile) phone to watch these IPTV broadcasts. Internet television 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. 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

Telephone companies will most likely be the first ones to offer IPTV service. Later on, this facility will be extended to other current television carriers. IPTV is not a costly affair, and it is even both operator and consumer friendly. Because it uses the Internet and sends less information compared to standard analog or digital television, IPTV promises both lower costs for operators and lower prices for consumers. The use of set-top boxes through broadband or DSL Internet is very helpful to transfer video signals. Therefore, video can be streamed to households more efficiently compared to signaling by coaxial cable. In addition to its higher speed, it can record multiple programs at once by use of digital video recorders (DVR). In ROI terms, the copper was already paid for by the phone service and the fiber/DSL by the broadband service. Therefore, IPTV only has incremental costs.

The IPTV architecture consists of the following functional components:

IV.i. Content Sources:

The 'Content Source' is defined as a functionality which receives video content from producers and other sources. Afterwards, these contents are encoded and store in an acquisition database for video-on-demand (VoD)

IV.ii. Service Nodes:

The 'Service Node' is defined as a functionality, which receives video streams in different formats. These video streams in different formats then reformat and encapsulate it for transmission with appropriate quality of service (QoS) indications to the wide-area network. This makes it ready for delivery to customers. In regards to service management, the Service Nodes communicate with the customer premises equipment (CPE); for the subscriber, session and digital rights management, service nodes communicate with the IPTV service.

IV.iii. Wide Area Distribution Networks:

The Wide Area Distribution Network is made up of distribution capability, capacity, and quality of service. It also consists of other capabilities, such as multicast, which is necessary for the reliable and timely distribution of IPTV data streams from the service nodes to the customer premises. Moreover, the core and access network cover the optical distribution backbone network and the various digital subscriber line access multiplexes (DSLAMs). This is located at the central office or remote distribution points.

IV.iv. Customer Access Links:

In the customer access links, high-speed DSL technologies such as ADSL2+ and VDSL are required; with the help of such technology, customer delivery can be provided over the existing loop plant and through phone lines to homes. There are some other options available. Service providers may use a combination of fiber-to-the curb (FTTC) and DSL technologies for delivery to customers. They can also implement direct fiber-to-the-home (FTTH) access. However, good results depend on the richness of their IPTV service offerings.

IV.v. Customer Premises Equipment (CPE):

In context of IPTV, the CPE device is located at the customer premises. This provides the broadband network termination (B-NT) functionality. At a minimum, it may also include other integrated functions, which can be routing gateway, set-top box, or home networking capabilities.
IV.vi. IPTV Client:

The IPTV client is a functional unit, which terminates the IPTV traffic at the customer premises. This is only a device, such as a set-top box, which performs the functional processing. The functional processing includes setting up the connection and QoS with the service node, decoding the video streams, channel change functionality, user display control and connections to user appliances such as a standard definition television (SDTV) or a high definition television (HDTV) monitor.

IV.vii. MPEG-4

Is a standard used primarily to compress audio and video (AV) digital data Introduced in late 1998, it is the designation for a group of audio and video coding standards and related technology agreed upon by the ISO/IEC Moving Picture Experts Group (MPEG). The uses for the MPEG-4 standard are web (streaming media) and CD distribution, conversation (videophone), and broadcast television, all of which benefit from compressing the AV stream.MPEG-4 absorbs many of the features of MPEG-1 and MPEG-2 and other related standards, adding new features such as (extended) VRML support for 3D rendering, object-oriented composite files (including audio, video and VRML objects),support for externally-specified Digital Rights Management and various types of interactivity. AAC (Advanced Audio Codec) was standardized as an adjunct to MPEG-2 (as Part 7) before MPEG-4 was issued. Most of the features included in MPEG-4 are left to individual developers to decide whether to implement them. This means that there are probably no complete implementations of the entire MPEG-4 set of standards. To deal with this, the Standard includes the concept of "profiles" and "levels", allowing a specific set of capabilities to be defined in a manner appropriate for a subset of applications.

IV.viii. Set Top Box (STB)

An electronic device that adapts a communications medium to a format that is accessible by the end user. Set top boxes are commonly located in a customer’s home to allow the reception of video signals on a television or a computer. The STB is the gateway to an IP video switching system. The viewer's TV connects to a Set Top Box (STB) that decodes the IP video and converts it into standard television signals. The Switched Video Service (SVS) system allows viewers to access broadcast network channels, subscription services and movies on demand. The consumer can access different media by using the television remote to send control commands to the SVS. The unit processes the request and displays the requested media type. Though there are many possible media sources, only one video channel is utilized in the process.

VI. PROTOCOL

As already discussed, IPTV covers both Live TV, i.e., multicasting, as well as stored video or VoD. The requirements for playback of IPTV are either a personal computer or a "set-top box" connected to a TV. Typically, the video content is a moving pictures expert group (MPEG) 2-transport stream (TS) delivered via IP multicast. This is a method in which information can be sent to multiple computers at the same time, with the newly released H.264 format predesigned to replace the older MPEG-2. In standard-based IPTV systems, the primary underlying protocols used for IPTV are Internet group management protocol (IGMP) and real time streaming protocol (RTSP). Here, IGMP is the version 2 for channel change signaling for Live TV and RTSP for VoD.

Currently, only one alternative exists to IPTV which is the traditional TV distribution technology covering terrestrial, satellite and cable TV. However, when there is a possibility for the cable TV, it can be upgraded to two-way capability system and thus also carry IPTV. Another alternative available is VoD which is usually delivered in the US over cable TV through the digital video broadcasting (DVB) protocol, but it is not labeled as IPTV services.


VI.i. IGMP2

The Internet Group Management Protocol (IGMP) is a communications protocol used to manage the membership of Internet Protocol multicast groups. IGMP is used by IP hosts and adjacent multicast routers to establish multicast group memberships. It is an integral part of the IP multicast specification, like ICMP for unicast connections. IGMP is used for online video and gaming, and allows more efficient use of resources when supporting these uses.
IGMPv2: Leave messages were added to the protocol. IGMPv2 allows group membership termination to be quickly reported to the routing protocol, which is important for high-bandwidth multicast groups and/or subnets with highly volatile group membership. Like ICMP, IGMP is an integral part of IP. It is required to be implemented by all hosts wishing to receive IP multicasts. IGMP messages are encapsulated in IP datagram’s; with an IP protocol number of 2. All IGMP messages described in this document are sent with IP TTL 1, and contain the IP Router Alert option in their IP header.


VI.ii. RTSP

The Real-Time Streaming Protocol allows controlling multimedia streams delivered, for example, via RTP. Control includes absolute positioning within the media stream, recording and possibly device control. The Real Time Streaming Protocol (RTSP), developed by the IETF and published in 1998 as RFC 2326, is a protocol for use in streaming media systems which allows a client to remotely control a streaming media server, issuing VCR-like commands such as "play" and "pause", and allowing time-based access to files on a server. Some RTSP servers use RTP as the transport protocol for the actual audio/video data. Many RTSP servers use Real Network’s proprietary RDT as the transport protocol. RTSP commands. RTSP requests are based on HTTP requests. While HTTP is stateless, RTSP is a stateful protocol. A session ID is used to keep track of sessions when needed. This way, no permanent TCP connection is needed. RTSP messages are sent from client to server, although some exceptions exist where the server will send to the client. Below are the basic RTSP requests. A number of typical HTTP requests, like an OPTION request, are also frequently used.

A DESCRIBE request includes an RTSP URL (rtsp://...), and the type of reply data that can be handled. The reply includes the presentation description, typically in SDP format. Among other things, the presentation description lists the media streams controlled with the aggregate URL. In the typical case, there is one media stream for audio and one for video.

A SETUP request specifies how a single media stream must be transported. This must be done before a PLAY request is sent. The request contains the media stream URL and a transport specifier. This specifier typically includes a local port for receiving RTP data (audio or video), and another for RTCP data (meta information).The server reply usually confirms the chosen parameters, and fills in the missing parts, such as the server's chosen ports. Each media stream must be configured using SETUP before an aggregate play request may be sent.

A PLAY request will cause one or all media streams to be played. Play requests can be stacked by sending multiple PLAY requests. The URL may be the aggregate URL (to play all media streams), or a single media stream URL (to play only that stream). A range can be specified. If no range is specified, the stream is played from the beginning and plays to the end, or, if the stream is paused, it is resumed at the point it was paused.

A PAUSE request temporarily halts one or all media streams, so it can later be resumed with a PLAY request. The request contains an aggregate or media stream URL. When to pause can be specified with a range parameter. The range parameter can be left out to pause immediately.

The RECORD request can be used to send a stream to the server for storage.

A TEARDOWN request is used to terminate the session. It stops all media streams and frees all session related data on the server.


VII. APPLICATION & SERVICES

The applications for IPTV deployment are to provide the delivery of digital broadcast television and also the selected VoD. Such application enables service providers to offer the so-called "triple play," which is video, voice and data. The IPTV infrastructure also provides additional video applications mostly after the installation of IPTV infrastructure is in place. Now, let us take a look at the major applications and services enabled by IPTV.

VII.i. Digital Broadcast TV

Customers get a conventional digital television through IPTV. This digital broadcast TV is delivered to subscribers via an upgraded cable TV plant or through satellite systems. The initiation of higher-speed DSL technology such as ADSL2, ADSL2+ and VDSL has brought a revolution to this field. This higher-speed technology enables IPTV to be a convincing and highly competitive substitute for customers. Today, a number of telecom service providers are testing, planning, and building collaborations around IPTV throughout North America, Europe, and Asia.

IPTV has the full potential to offer various high-quality services and much more than what traditional broadcast, cable, and satellite TV providers have offered subscribers in the past. Another utility with IPTV is that it has more content variety with a larger number of channels to choose depending on the customers' preferences. This makes a promising start especially as customers can choose from its diversified content. It will reach its target group no matter whether the subscribers are in the mass markets, in specialized groups, or spread out in demographic communities.

The function of conventional broadcast, cable, and satellite TV is to provide all channels simultaneously (i.e., broadcast) to the subscriber home. However, IPTV is unique and different from all conventional groups. IPTV only delivers those channels which are being viewed by the subscriber and has the potential to offer practically an 'unlimited' number of channels. The IPTV consumers will get the freedom to control what they want to watch and also when they want to watch. This is possible because it has a combination of two-way interactive capability. This is inherent in IPTV because of its association with IP. This association is built-in and tied to a robust internal network. Therefore, subscribers are enjoying the facility to broaden the unique experience at home or in their business.

VII.ii. Video on Demand

VoD is a service, which provides television programs per the demands of the subscribers. The users interactively request and can receive television channels. These television services are beamed from previously stored media consisting of entertainment movies or education videos. It has a live access through live connection, such as news events in real time. The VoD application provides freedom to the individual subscribers to select a video content and view it at their convenience.

When the initial IPTV infrastructure is in its place, IPTV applications and potential revenue-generating services, such as video telephony and video conferencing, remote education, and home security/monitoring cameras, will be available. There are also some additional features and services available, which are much more advanced in comparison to traditional broadcast television systems. In addition to providing the basic television services and features, we think of these as VOD, time shift TV and Network PVR…all based on the Media Server approach.

VII.iii. Any where Television Service

Anywhere Television Service uses television extensions, which are the viewing devices that can be connected to the system of a television distribution. There are two options in this regard:
(1) These connections may be shared, for example, by several televisions on the same line or
(2) They may be controlled independently, such as the case of a private television system.
Conventionally, television extensions have a fixed wire or a connection line. This is because:
(1) It allows a television viewing device to either share (i.e., directly connect to) another communication line
(2) It allows an independent connection it to a switching point (such as a private company television system).
In IPTV, when an IP television viewer is connected to a data connection for the first time, it sends the request to an assignment of a temporary Internet address from the data network. After its connection to the Internet, it uses the said Internet address to get registered with the Internet Television Service Provider (ITVSP). The reason is that the ITVSP is always aware of the current Internet address, which is assigned to the IP television each time it has been connected to the Internet. This also allows IP televisions to operate at any connection point that is willing to provide it broadband access to the Internet. In real meaning, this allows an IP television to operate like a television extension, which can be plugged in anywhere in the world.

VII.iv. Global Television Channel

The name indicates, global television channels are TV channels that can be viewed globally. IP television channels are beamed through the Internet and, as it offers broadband data access, it can thus be typically viewed in any part of the globe.
The IP television system is capable of providing video service outside the purview of their local, often regulated, areas. This ability makes IP television a very competitive tool around the world. The typical cost for viewing global television channels is the content media access costs, for example, the cost or fee for watching a movie. Moreover, the cost includes the broadband data access cost, which is a monthly charge for broadband access.

VII.v. Personal Media Channels (PMC)

A communication service which is user friendly to subscribers. It allows a media user, for example, to select and view media from different media sources such as video or music. Here is an example how a PMC may be used for IP television. The control and distribution of mixed media, such as digital pictures and digital videos, can be done through a personal television channel for the service of friends and family members. In this regard, an IP television customer can be assigned a personal television channel. Then, the user can upload media to their personal media channels and can thus allow friends and family to access their pictures and videos. This is done via their IP televisions.

VII.vi. Addressable Advertising

The well-knit communication of a particular message or media content between a specific device and the customer based on their address is called addressable advertising. Here, the said address of the customer may be obtained by scrutinizing the profile of the viewer. This is done in order to determine whether the advertising message is appropriate for the recipient or not. Therefore, addressable advertising allows for speedy and straight measurement of the efficiency of advertising campaigns.
The cooperation of the viewer is the key aspect of addressable advertising. As soon the IP television is turned on, the IP television systems may ask or prompt the viewer to pick their name from a list of registered users. As a reply, viewers will typically want to select their programming name. Here, the programming name has a profile (or, preferences) and the advertising messages can be selected, which are the best match to the concerned viewer profile. Because of the advanced features offered by IP television, such as incoming calls and e-mails and programming guides that remember favorite channels, the viewers can actually do so here.
The generated revenue for addressable advertising messages sent to viewers with specific profiles can be 10 to 100 times higher than the revenue for broadcasting an advertisement to a general audience. The ability to send commercial advertisements to a specific number of viewers allows the advertisers to fix a precise budget for addressable advertising. It also allows the advertiser to experiment a number of different commercial advertisements in the same geographic area at the same time.

VII.vi. Multicast

By using the IP multicast feature in providing an IPTV service, a service provider can conserve bandwidth in their core and access networks. When more than one user is viewing the same channel in a home network, the service provider may only deliver a single video stream. But, at the same time, the home network technology must be competent to distribute this towards multiple users on the home network.
Imagine the core requirements for bandwidth if all customers are watching a different time-shifted channel to when they wanted to watch. Both Multicast and Unicast are needed in the IPTV world, but the former is quicker and easier to deploy in terms of core network capacity than the latter which mostly requires a dedicated one-to-one relationship from customer to server.

VII.vii. Privacy and Security

Let us look at the important aspect of privacy and security of the subscribers. In this regard, the home network must be a closed one. Where is the user's security in this regard? It should be a secure network where access is limited only to users and concerned devices within the home. This is an important factor for the home networks as it uses wireless technologies or shared media technologies such as power line networking. Further, the user data on the home network is protected and no outsiders or intruders have the power to intercept. Unauthorized users do not have the capacity to view it.


VIII. ADVANTAGES OF IPTV

There are several advantages to IPTV, including Interactivity, Video-on-Demand (VoD), better compression technologies, and triple play efficiencies. Other advantages include better program guides.

VIII.i. Interactivity

IPTV provides two-way capabilities, lacked by traditional TV distribution technologies. Interactive television allows for signals to be sent back up to the TV provider which can be used in many ways - such as altering what you are watching (eg: switching camera angles or commentators on a sporting event), requesting more information (eg: interactive news, or advertising), or for statistics.

VIII.ii. VoD

IPTV allows for point-to-point distribution, allowing each viewer to view individual broadcasts (VoD, or Video on Demand). This enables stream control (pause, wind/rewind etc.) and a broad selection of programming much like its narrowband cousin, the web. IPTV can emulate Digital Video Recorders (DVR), such as TiVo, and may also download programs to a hard disk for local control.


VIII.iii. Better Compression
IPTV uses a more efficient compression standard than FTA digital television, resulting in smaller file sizes or higher quality TV.

VIII.iv. 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 Telco’s are starting to offer all 3 on one wire, which is more cost effective. Triple play is an expression used by service operators describing a package 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.

VIII.v. IPTV Based Converged Services

One of the important services that many Telcos are harping upon for drawing on new revenue streams is Converged Services. 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 ability to handle it(send it to Voice mail etc).