OVERVIEW OF HD CAPABLE IP SET-TOP BOXES (STB)

- HD capable IP set-top boxes - are a fast growing sector in the consumer electronics marketplace. HD capable set-tops typically deliver enhanced HD video and audio to consumers. These types of IPTVCDs not only allow viewers to watch high quality HD transmissions but also standard definition programming content as well. HD capable IP set-top boxes are typically classified as follows.

















- HD Multicast Only Boxes - These set-tops are capable of receiving HD channels via a number of different types of IP broadband access networks.

- HD Set-tops with Hard Drives - This type of IP set-top box is able to replicate PClike functionality and allow consumers to personally record HDTV video content and cache HD multicast programming content.

- HD Set-tops with Integrated Recording Unit - HDTV consumes huge amounts of network capacity. A typical HDTV MPEG-2 stream is transmitted at over 20 Mbps. To record 1 h of this stream, over 6 GB of storage would be required. Despite the high capacity storage required, the demand from consumers for solutions, which allow recording of HD content, is rising. Traditional storage media devices such as CD-ROMs are not capable of archiving these volumes of data. Therefore, manufacturers have started to build HD capable set-top boxes that include an optical recording unit that allows consumers to securely record content onto a hard disk or writeable DVDs. These disks can then be played on other devices such as PCs, notebooks, or portable DVD players. In addition to recording material these units are also able to play off-the-shelf DVDs and CDs. These devices support next generation optical disk formats, namely, Blu-ray and HD-DVD.

BLU-RAY Blu-ray, also known as Blu-ray Disc (BD), is a next generation storage format that is used by optical disks to store up to 50 GB of data. The standard is developed and promoted by a group of consumer electronics, personal computer,and media manufacturers called the Blu-ray Disc Association (BDA). HD capable IP set-top boxes that are equipped with Blu-ray compliant units are able to directly record, rewrite, and store large amounts of high quality HD video content.

HD-DVD Some HD capable IP set-top boxes come with a DVD recording unit that supports a format called HD-DVD. Similar to Blu-ray the HD-DVD storage medium also allows the recording, delivery, and storing of HD digital video content onto optical disks.

All of the above IP HD set-top boxes receive the HDTV signal from a IP broadband network. The set-top box then decodes the signal and streams the output to a display. The format of the signal outputted depends on the capabilities of the display device used in the consumer’s household. For instance, advanced flat panel displays such as plasma screens can support HD broadcasts in their original studio format, whereas a standard TV will only be able to view a scaled down version. As HDTV services become more advanced, the set-top industry needs high performance technologies to support the decoding of high definition video streams.

An IP HD capable digital set-top box hardware platform has similar features to cable, terrestrial, IP, and satellite set-top boxes. HD capable IP set-top boxes do however have some additional and unique characteristics that are used to deliver services such as high definition streaming video, improved digital audio, and connectivity to other in-home digital devices. These characteristics include advanced connectivity ports and a sophisticated security system for protecting content outputs.

AN END-TO-END IP HDTV SYSTEM

In general the protocols used to transport SDTV signals across an IP network
are the same used in the delivery of HD video content.
























HD Enabled Digital Cameras

HD cameras are been used by a growing number of film production companies. These types of cameras shoot video content up to five times the resolution of SDTV. The content from a HD camera typically gets digitally transferred to a server using fiber optic cable.


HDTV Servers

The HDTV server is connected via a high speed broadband network to an HD capable IP set-top box or a standard PC. Its main function is to digitally store HDTV content on a high capacity storage device.


Encoders

MPEG-2 encoders are the most common format for compressing SDTV. The processing of a high definition MPEG-2 video channel can use up to six times the amount of bandwidth of a standard channel. A number of telecommunication providers have limited bandwidth capacity on their networks to support MPEG-2 compressed high definition content. Therefore HD capable encoders play an important role in the HDTVenvironment and are responsible for achieving the best picture quality at the lowest bit rate. Most encoders used to deliver IP HDTV content are based on advanced encoding algorithms such as MPEG-4 and VC-1. These encoding technologies promise to deliver better video quality at lower bandwidth capacities.


A High Capacity IP Network

A HD video file can include up to five times the information of an SDTV file. Therefore, a high speed digital cable, satellite, DSL broadband, or terrestrial network with sufficient bandwidth capacity is required to transport HD content from the IPTV service provider’s data center to the HDTV home viewing system.

HDTV OVER IP DEFINED

- The acronym IP HDTV is typically used to describe the delivery of high definition video content over a broadband connection. It is a relatively new technology and is steadily taking off as a value added service for telecommunication companies who want to differentiate their IPTV services from existing cable and satellite offerings.

- There are a number of reasons why service providers are upgrading their network architectures to support the transmission of HDTV content. The following is a short list of some of the most compelling ones.





















Improvement in Video Quality

The evolution from traditional analog TV to digital TV has already provided
consumers with sharper, richer, and more engaging video content. Continuing this
evolution from standard digital TV content to high definition broadcasting brings
the TV viewing experience closer to resembling the sharper and crisp video quality
provided by cinemas.


Better Color Resolution

The color resolution supported by HDTV is far superior to the resolution of regular SDTV video content.


Quality Levels

- By using advanced compression technologies in conjunction with high speed networking technologies, it is now possible to provide consumers with IP HDTV services at reasonably high quality levels. The delivery of HD content over an IP broadband platform comes with a number of challenges including:

. HDTV has greater bandwidth requirements compared to SDTV video streams. As such the networking infrastructure needs to be upgraded to provide sufficient bandwidth to deliver multiple HDTV streams into people’s homes. The amount of bandwidth required depends on the compression algorithm applied to the content at the IPTV data center. Higher compression rates
require less bandwidth; however, final picture quality is degraded.

. The reception system at the IPTV data center may need to be upgraded to support and manage larger volumes of video data. Additionally, extra storage resources are also required to accommodate increased file sizes, which is a ‘‘feature’’ of HD video content.

. The internal networking infrastructure of the IPTV data center needs to support very high transfer rates. This may require an upgrade to the existing cabling infrastructure.

. IPTV end users need to either lease or buy HD capable TVs and set-top boxes to enjoy the full benefits of IP HDTV.

OVERVIEW OF SDTV AND HDTV TECHNOLOGIES

SDTV is a digital TV broadcast system that provides consumers with better pictures and richer colors than analog TV systems. Digital technology is also capable of producing HDTV pictures with more image information than conventional analog signals, producing an effect that rivals the movie theater for clarity and color purity.

Although both systems are based on digital technologies, HDTV generally offers viewers nearly six times the sharpness of SDTV based broadcasts. In addition to classifying digital TV signals into HDTVand SDTV, each of these technologies has the following subtype classifications.



































Resolution

- Resolution is defined as the amount of detail or pixels contained in an image displayed on a television set. This characteristic is one of the main reasons why people experience an improved viewing experience while watching a HDTV in comparison to standard analog based TVs. A television display has display capabilities of 644 x 483 pixels, although most people refer to it as 640 x 480. This again is not a true description of the display capabilities of a standard TV. For technical reasons, most viewers are unable to see the margins that surround the perimeter of their television screens. Consequently, most industry experts calculate the actual viewing area by subtracting the marginal areas. Such calculations result in an actual viewing area on a standard TV of 620 x 440 pixels. It is also possible to measure the resolution of a television display by the number of video lines available on the screen. The video lines are developed with a type of electronic gun that operates inside the television tube. This gun emits a beam of light that moves back and forth across the surface of the screen. As the beam moves across the inner surface of the screen, it creates an image, line by line.

As a general rule, the more lines created by the gun, the higher the resolution. The resolution of an IP HDTV program is dependent on the size of the TV display and the number of video lines present on the screen.

For example, clearer pictures are available to owners of new HD televisions because they are able to display 1080 lines of resolution versus 525 lines displayed on an ordinary television sets.


Interlaced and Progressive Scanning

- The process of scanning defines how the lines are displayed across a TV screen. There are two different scanning methods, namely, interlaced and progressive. Interlacing scanning is a system that was designed by TVengineers to overcome the inability of early television tubes to draw a video display on the screen before the top of the display began to fade. With interlacing the image is created by instantaneously applying light to every second line on the screen. Once this is completed the remaining lines are illuminated almost immediately. This happens so fast that
the human eye is unable to detect. Interlace scanning is popular in analog televisions and low resolution computer monitors.

Progressive scanning, also known as noninterlaced video, refers to a process of a television screen refreshing itself line by line. This is done at the same time therefore the image appears smooth to the human eye and stays sharp during motion in the video pictures. Progressive scanning is popular in HDTVs and computer monitors.


Aspect Ratio

- Aspect ratio defines the relationship between the horizontal width and vertical height of a TV screen. The aspect ratio of a traditional TV screen is 4 : 3. In other words, for every four units of measurement across the length of the TV screen the height will consist of three units. HDTV uses an aspect ratio of 16 : 9.

These classifications are used by broadcasters and TV manufacturers to define a notation for identifying different types of HDTV products. The notation used in the United States is based on lines of resolution followed by a letter that represents the type of scanning used. An ‘‘i’’ represents interlaced and a ‘‘p’’ represents progressive. The notation also includes a figure for the number of frames or fields per second. Examples of some of the most popular HDTV standards.

IPTV NETWORK DISTRIBUTION TECHNOLOGIES

It looks like IPTV is well on its way to becoming a popular means for delivering digital TV services to consumers. Owing to the nature of IPTV, a high speed distribution networking platform is required to underpin the delivery of IP based content. The purpose of this network is to move bits of data back and forth between the IPTV consumer device and the service provider’s IPTV data center. It needs to do this in a manner that does not affect the quality of the video stream delivered to the IPTV subscriber, and it is up to each IPTV provider to decide on the type and sophistication of the network architecture required to support their IPTV services.

An IPTV network architecture consists of two parts the “last mile” broadband distribution and the centralized or core backbone. A wide variety of networks, including cable systems, copper telephone, wireless, and satellite networks may be used to deliver advanced IPTV network services over the last mile section of the network. The delivery of video over all of these different types of networks comes with its own set of challenges. The majority of this chapter focuses on describing these key technology platforms. Once the key delivery platforms are covered, the chapter concludes with an analysis of the two primary core networking technologies and a brief overview of network factors that affect the deployment of IPTV services.

“LAST MILE” BROADBAND DISTRIBUTION NETWORK TYPES

One of the primary challenges faced by IPTV service providers is providing enough bandwidth capacity in the network segment that lies between the core backbone and the end-users’ home. A number of terms are used to describe this segment ranging from local loop and last mile to edge and broadband access network.

There are six different types of broadband access networks that are scalable enough to meet the
bandwidth requirements of IPTV:

. Through a network built with fiber
. Via an DSL network
. Via a cable TV network
. Via a satellite based network
. Via a fixed wireless broadband connection
. Via the Internet


Different service providers operate each system. The following sections give a
technical overview of these platforms when used in an IPTVend-to-end networking
infrastructure.

KEY IPTV APPLICATIONS AND SERVICES

1.Broadcast Digital TV

the European Digital Video Broadcasting (DVB) project was born. In 1996, the FCC established digital television transmission standards in the United States by adopting the Advanced Television Systems Committee (ATSC) digital standard. As of 1999, many communication mediums have transitioned to digital technology. In recent years, a number of countries have started to launch standard definition and high definition TV services and are acting as the primary driving force behind a new type of television systems liquid crystal display (LCD) panels and plasma display panels (PDPs).

1.1 Benefits of Digital TV Transmissions

When compared to analog technology the broadcasting of television in computer data format provides digital TV viewers and service providers with a number of benefits.

Improved Viewing Experience The viewing experience is improved through cinema quality pictures, CD quality sound, hundreds of new channels, the power to switch camera angles, and improved access to a range of exciting new entertainment services, additionally, any of the picture flaws that are present in analog systems are absent in the new digital environment.

Improved Coverage Both analog and digital signals get weaker with distance. However, while the picture on an analog TV system slowly gets worse for viewers that live long distances away from the broadcaster, a picture on a digital system will stay perfect until the signal becomes too weak to receive.

Increased Capacity and New Service Offerings By using digital technologies to transmit television, service providers can carry more information than is currently possible with analog systems. With digital TV, a movie is compressed to occupy just a tiny percentage of the bandwidth normally required by analog systems to broadcast the same movie.

The remaining bandwidth can then be filled with programming or data services such as
. Video on demand (VoD)
. E-mail and Internet services
. Interactive education
. Interactive TV commerce

Increased Access Flexibility Traditionally, it was only possible to view broadcast quality analog content on a TV set. With the introduction of digital technologies, video is accessible on a whole range of devices ranging from mobile phones to standard PCs.

Note that eventually, all analog systems will be replaced with digital TV. The transition from analog to digital will be gradual to allow service providers to upgrade their transmission networks and for manufacturers to mass produce digital products for the buying public. In development for more than a decade, the digital TV system that has evolved today is the direct result of work by scientists, technologists, broadcasters, manufacturers, and a number of international standard bodies. Till a couple of years ago it was only practical to use radio frequency (RF) based signal technologies to deliver digital TV to consumers. Recent advancements in compression and broadband technologies are however changing this situation,
and many service providers have started to use IP based networks to deliver broadcast digital TV services to their customers.

2.Video on Demand (VoD)

In addition to allowing telecommunication companies to deliver linear TV channels to their subscribers, IPTV provides access to a wide range of downloadable and VoD based content. In contrast to traditional TV services where video programs are broadcasted according to a preset schedule, VoD provides IPTV end users with the ability to select, download, and view content at their convenience. The content delivered through an IPTV VoD application typically includes a library of ondemand movie titles and a selection of stored programming content. Facilitating access for VoD is a pretty major challenge for all telecommunication companies. For a start, broadband subscribers that regularly access on-demand content consume huge amounts of bandwidth. On top of this the server architecture required to stream video content to multiple subscribers is quite large.

OVERVIEW OF AN IPTV NETWORKING INFRASTRUCTURE

Picture shows the typical high level functional requirements of an end-to-end
IPTV system.





















1.3.1 IPTV Data Center

Also known as the “headend,” the IPTV data center receives content from a variety
of sources including local video, content aggregators, content producers, cable,
terrestrial, and satellite channels. Once received, a number of different hardware
components ranging from encoders and video servers to IP routers and dedicated
security hardware are used to prepare the video content for delivery over an
IP based network. Additionally, a subscriber management system is required to
manage IPTV subscriber profiles and payments. Note that the physical location of
the IPTV data center will be dictated by the networking infrastructure used by the
service provider.

1.3.2 Broadband Delivery Network

The delivery of IPTV services requires a one-to-one connection. In the case of a
large IPTV deployment, the number of one-to-one connections increases significantly
and the demands in terms of bandwidth requirements on the networking
infrastructure can be quite large. Advancements in network technologies over the
past couple of years now allow telecom providers to meet this demand for large
amounts of bandwidth networks. Hybrid fiber and coaxial based cable TV infrastructures
and fiber based telecommunication networks are particularly suited to the
delivery of IPTV content.


1.3.3 IPTVCDs

IPTV consumer devices (IPTVCDs) are key components in allowing people to access
IPTV services. The IPTVCD connects to the broadband network and is responsible
for decoding and processing the incoming IP based video stream. IPTVCDs support
advanced technologies that minimize or completely eliminate the effect of network
problems when processing IPTV content. As broadband starts to become a mainstream
service, the functionality of IPTVCDs continues to change and increase in
sophistication. The most popular types of IPTVCDs (residential gateways, IP set-top
boxes, game consoles, and media servers).

1.3.4 A Home Network

A home network connects a number of digital devices within a small geographical
area. It improves communication and allows the sharing of expensive digital
resources among members of a family. The purpose of a home network is to provide
access to information, such as voice, audio, data, and entertainment, between
different digital devices all around the house. With home networking, consumers
can save money and time because peripherals such as printers and scanners, as well
as broadband Internet connections, can be easily shared. The home networking
market is fragmented into a range of different technologies.

DEFINING IPTV

There is a lot of buzz and excitement at the moment with regard to IPTV. The technology is growing in importance and is starting to have a disruptive effect on the business models of traditional pay TV network operators.

But what does the IPTV acronym mean and how will it affect TV viewing? For a start, IPTV, also called Internet Protocol Television, Telco TV, or broadband TV, is about securely delivering high quality broadcast television and/or on-demand video and audio content over a broadband network. IPTV is generally a term that is applied to the delivery of traditional TV channels, movies, and video-on-demand content over a private network. From an end user’s perspective, IPTV looks and operates just like a standard pay TV service. 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.

From a service provider’s perspective, IPTV encompasses the acquisition, processing, and secure delivery of video content over an IP based networking infrastructure. The type of service providers involved in deploying IPTV services range from cable and satellite TV carriers to the
large telephone companies and private network operators in different parts of the world.

IPTV has a number of features:

. Support for interactive - two-way capabilities of IPTV systems allow service providers to deliver a whole raft of interactive TV applications. The types of services delivered via an IPTV service can include standard live TV, high definition TV (HDTV), interactive games, and high speed Internet browsing.

. Time shifting - IPTV in combination with a digital video recorder permits the time shifting of programming content - a mechanism for recording and storing IPTV content for later viewing.

. Personalization - An end-to-end IPTV system supports bidirectional communications
and allows end users personalize their TV viewing habits by
allowing them to decide what they want to watch and when they want to
watch it.

. Low bandwidth requirements - Instead of delivering every channel to every end user, IPTV technologies allows service providers to only stream the channel that the end user has requested. This attractive feature allows network operators to conserve bandwidth on their networks.

. Accessible on multiple devices - Viewing of IPTV content is not limited to
televisions. Consumers often use their PCs and mobile devices to access IPTV
services.