2   IPTV versus Internet Video

This is definitely the Wild West in some ways; it's in the very early stages, and people are still learning.

—Adam Berrey, VP of marketing and strategy, Brightcove,
in The Washington Post

Both IPTV and Internet Video use IP technology for video delivery, but that's where the similarities end. IPTV has similarities to traditional CATV, satellite and broadcast television, where continuous channels of programming are delivered to consumers for viewing on traditional television sets. In contrast, Internet Video delivers discrete pieces of content selected by individual viewers for viewing on a display connected to a personal computer. In terms of the range of content and amount of control, IPTV is like listening to music from a radio broadcast, whereas Internet Video is like listening to music on a personal MP3 player.

Both technologies have a role to play in video delivery. In Chapter 3, we will discuss ways that either IPTV or Internet Video can be used to create successful video delivery businesses. Many broadcasters will find themselves offering programming by means of one or both of these technologies; they are not mutually exclusive. Both forms of delivery can be useful for reaching different markets—or even a single group of consumers—who may want to view content in different ways at different times of the day. Broadcasters should become familiar with both IPTV and Internet Video technologies in order to position themselves to benefit as both markets mature.

This chapter is made up of two sections. In the first section, we will discuss the principal characteristics of an IPTV system. In the second section, we will discuss the different characteristics of an Internet Video System. At the end of the chapter, we will summarize the main differences in a table. In the Reality Check, we'll see how, even now, the differences between these two categories are starting to melt away.

Characteristics of IPTV

IPTV is primarily used to offer services that duplicate or exceed the features and functions of a CATV or direct broadcast satellite system by means of an IP network. Service providers who wish to deliver multiple consumer services over a single network often choose IP technology because it can provide voice and high-speed data access in addition to IPTV on a single platform. In a typical system, a private, high-speed IP network is used to continuously deliver video programming to hundreds or thousands of viewers simultaneously.

The typical IPTV network shown in Figure 2.1 is separated into three physical locations: the Video Serving Office (VSO), the Local End Office (LEO) and the viewer's home. The VSO is responsible for gathering video from a variety of sources and converting the signals into IP video streams. The LEO is responsible for combining video, data and voice signals into a form that can be transmitted over a network to the home. In this example, Digital Subscriber Loop (DSL) technology is being used, so the LEO contains a DSL Access Multiplexer (DSLAM) to format the signals. Inside the home, the incoming signal is split and reformatted for a number of purposes, including telephone service, high-speed data service and video that is fed to a television by way of an IPTV set top box (STB).

FIGURE 2.1   Typical IPTV Network

Many types of technology can be used to deliver IPTV service to the home, including DSL, fiber optics, wireless, CATV and even broadband over power lines. Regardless of the delivery technology, the basic characteristics of an IPTV network are quite similar, which we will now discuss in more detail.

Continuous Content Streams

IPTV is designed to send streams of video programming to each viewer. These streams are continuous—each viewer can select the stream they want to view, but they must join the stream in-progress. This process is functionally identical to the programming delivered by local broadcasters, CATV companies and satellite providers—the viewer is able to select the channel to be viewed, but not the content of the channels. This contrasts with Internet Video, where viewers generally select each piece of content they wish to view and play it in whatever order they want.

In most cases, the programming provided over IPTV systems is not created or owned by the IPTV provider. Instead, this programming is obtained from normal broadcast television sources, including broadcasters that may be located in the same city as the IPTV system. Broadcasters typically don't need to do anything special to their content to prepare it for broadcast on an IPTV network—the process of compressing the video and formatting it into IP packets is usually done by the IPTV network provider.

There is one significant exception to the practice of delivering continuous streams of programming to an IPTV viewer. Most IPTV systems also offer on-demand content, where viewers can select videos that are stored on a server and played out upon request. These videos can be from a wide variety of sources and may be offered for free or for additional cost to the viewer. With true on-demand content, viewers can control the playout of the video to start, stop, rewind and fast-forward through the content. As service providers expand their server capacities, more and more content will become available on-demand.

Multiple Channels

The content that is delivered over an IPTV network is produced by a range of broadcast networks and delivered simultaneously to a large number of viewers. When viewers watch this programming, they will see regularly scheduled news and entertainment from network such as NBC, BBC and TF1; live or recorded sports from companies such as ESPN or Premier; 24-hour news reports from CNN, Al Jazeera and others; and a variety of specialized programming such as music video channels, movie channels, children's channels and home shopping channels.

IPTV networks are well-suited to deliver live programming such as sports or award shows to many viewers at the same time. Hardware inside the network is capable of making copies of the continuous content streams and delivering them to hundreds or thousands of homes simultaneously.

Viewers typically choose which channel they want to watch on their television by interacting with the IPTV STB. This can by done by simply entering the desired channel number on a remote control keypad or by making a selection from an Electronic Program Guide (EPG). An EPG can be as simple as a “barker” channel that passively scrolls though all of the current channel choices, or it can be interactive, enabling the viewer to navigate through a list of choices.

Once the viewer has chosen a channel, the STB must connect to the IP stream that contains the appropriate video data and use this data to create a video signal that is sent to the viewer's television. In cases where this data is already present at the input to the STB, the switch can be accomplished merely by changing to the desired data stream. Otherwise, the STB must signal the DSLAM (or other IP switching device further upstream) to deliver the new data to the STB. This is particularly common on networks with limited bandwidth connections to each home, such as DSL networks.

Uniform Content Format

Most IPTV systems use only one (or possibly two) video encoding formats for each type of content. The choices can typically range from MPEG–2 or MPEG–4 to VC–1 (which began life as Windows Media 9), but IPTV providers will typically choose one format for all video signals. This greatly simplifies the overall management of the IPTV system, allowing for a uniform system design and easing the burden on technicians maintaining the system. This also simplifies the STB design by eliminating the need to support multiple video decompression engines.

Any content that arrives at the IPTV provider that is not in the correct format must be converted. There are two main methods to do this. The first involves taking the incoming video feed and decompressing it to a baseband digital video signal before recompressing it using the desired compression system. The second is a process called transcoding, where the signal remains in a compressed state but is processed and reformatted into the new format.

Most IPTV providers also convert all of the incoming content into a common bit rate, usually one value for SD and a second for HD. This greatly simplifies the process of channel changing and overall bandwidth management; one fixed-bandwidth stream replaces another stream of the same bandwidth when a viewer switches channels. The process of changing the bit rate of video stream is called transrating.

Private Network Delivery

In order to deliver continuous channels of content to thousands of viewers in a repeatable manner, an IPTV network must be carefully provisioned and controlled. This task is daunting on a private network where all of the video content and other network traffic can be controlled. This task would be impossible on the Internet.

Playing a continuous video stream is a constant race against time. The video source signal must be received, compressed (usually) and converted into IP packets that must be delivered to every viewer's STB just when they are needed to create the video signal. If the packets arrive too early, they must be stored in the STB until they are needed. If the packets arrive too late, then the video signal playout can be interrupted. Some of these variations can be smoothed out using a memory buffer inside the STB, but that step adds delay in the end-to-end delivery path and can slow channel changing.

To keep the streams moving smoothly, the IPTV network must be managed to ensure that the IP connections to each STB are not overcrowded with packets. Overcrowding can be disastrous in an IPTV network, because it can affect all of the packet streams, causing delays or even packet deletions that will surely affect the quality of the delivered video. On a private network, this can be avoided with careful engineering and by ensuring that each of the packet sources and destinations is controlled to prevent more packets from entering the network than can be delivered. In a public network that contains packet sources and destinations that can't be controlled by the IPTV provider, there is no mechanism to prevent overcrowding.

Viewed on Consumer Televisions via Set Top Boxes

Standard consumer television sets, until recently, have been very dumb devices when it comes to intelligently managing content. There is no mechanism to store video signals—any valid input is immediately displayed to the viewer. For most consumers, the television is located far away from the nearest PC, and many consumer PCs simply aren't up to the task of delivering high quality, full-screen, full-resolution video to the viewer. This is where the specialized hardware and software of an STB come into play.

The role of an STB is extremely important for an IPTV network. At a minimum, it must receive an incoming IP video stream, reassemble the data packets in the correct order, decode the video signal and produce an output that can be fed to a television (or projector) for display. It normally serves as the terminus for the IPTV network, so it must be able to receive commands from the user's remote control and send them into the network for action. It may also need some built-in intelligence to be able to generate text or other display used to communicate with the viewer, for functions like the EPG.

Internet Video

The viewer experiences and expectations for Internet Video are very different from IPTV. Most viewers have much lower expectations for Internet Video, particularly if they have ever tried to watch video over a dial-up connection. Of course, technology marches on, and the viewer experience continues to improve. Figure 2.2 shows a very simplified view of an Internet Video network.

This diagram contains two sections: production and distribution. In production, the video content is captured from a source, digitized, edited, labeled and bundled into a file that is placed on a server where it can be accessed. In distribution, a viewer uses an Internet-connected PC to search for content, connect to the server, acquire rights to view the content, and then either download a video file or request a video stream of the content for viewing on their PC using specialized multimedia viewing software.

FIGURE 2.2   Typical Internet Video Network

A viewer using their PC or other device initiates a typical viewing session. First, the viewer must identify where the content is located on the Internet. For example, a user might have received an e-mail from a friend with a link to a Web site containing the video. When the viewer clicks on the link, the browser on their PC connects to the appropriate Web server. Typically, the Web server then displays a screen that gives some information about the video (such as a description and the clip's duration). The viewer then may be asked to click on a link embedded in that page, which begins the video playing process. One important step that happens at this time is an exchange of information between the server and the browser software on the PC that tells the browser to run a plug-in or stand-alone application called a media viewer. The media viewer will properly decode the incoming video data and convert it into an image that can be displayed. If the proper media viewer software isn't installed on the PC, the user will be prompted to install it by downloading the software from a suitable source. Then, as the video file is delivered, the viewer can watch the content.

Discrete Content Elements

Instead of continuous channels of highly produced programming, most Internet Video content is available for each viewer to select exactly what they want to watch at whatever time is convenient. Many of the video files that are available for viewing or downloading are relatively short—five minutes or less. Certainly, longer duration files are available, but they tend to be more limited in number, particularly considering the cost of server and network bandwidth needed to deliver these streams over the Internet.

Not all Internet Video is discrete content elements—there are some real-time streaming broadcasts available. For example, NASA TV offers some live video content each day from the International Space Station, as well as live coverage of major events like shuttle launches and space walks (visit www.nasa.gov/multimedia/nasatv). In between, educational, news and other programming are provided. For-profit real-time Internet Video channels are also becoming a reality, as the number of viewers with high-bandwidth Internet connections reaches a level that is attractive for subscription or advertising-based services. (See the discussion of MobiTV in the Reality Check.)

Millions of Content Offerings

Any quick search of some of the more popular lists of video content on the Internet will show that there are well over a million different video files available for viewing, with thousands more being added each day. These can range from professionally produced music videos and movie previews to crude home videos and other amateur content. A great deal of content is available for free viewing; other files require purchase to view. Some sites allow the content to be downloaded for later playback; other sites only allow viewers to watch the content while they are connected to the site.

Locating a specific piece of content for viewing can be a challenge with Internet Video. Many viewers find content by following links on Web pages that direct them to video content sites. Others use the listings of popular titles on these Web sites. Still other viewers find the videos to watch using general-purpose search engines (such as Google) or site-specific search engines provided on some of the popular video Web sites. Unlike IPTV, there is no master EPG for the Internet—there's simply too much new content being added each day for this to be practical.

Multiple Content Formats

There are a wide variety of formats that can be used for video files, and virtually all of them have found their way onto the Internet. There are many choices, including various camera formats (such as DV), the MPEG family (1, 2 or 4), JPEG (basic or 2000), player-specific formats (Windows Media, QuickTime, Real Networks, etc.), and a variety of computer file formats (such as AVI and Flash). Consumers who view a significant amount of Internet Video content often end up with a collection of video players loaded onto their machines to handle the various video file formats.

For content providers, this variety can present a dilemma. If the provider chooses only to support a single video format, then any consumer who wishes to watch the content must already have the appropriate viewer software installed on their PC or find a way to get the proper viewer (most of which are distributed for free). If, on the other hand, the provider chooses to support multiple formats, then they assume the burden of producing and managing content in several different formats.

In addition to the choice of video compression technology, content providers must choose the screen resolutions they will support. Low resolutions offer small file sizes that are easier to download over low-bandwidth network connections but also create small images for viewing. Higher resolutions offer increased picture quality but can require a long time to download or a high-bandwidth connection for live streaming.

Delivered over the Internet

One big strength of Internet Video is that it can be delivered to any viewer with a connection to the Internet. Of course, high-bandwidth connections are easier to use and deliver quicker results, but even consumers with low-speed dial-up connections can download video files if they are patient enough.

Because video sites can be accessed from around the globe, the potential audience for any video can be very large, particularly if there is a good mechanism in place to inform consumers about the content that is available.

Use of the Internet also means that content providers don't need to build network facilities to all of their viewers, resulting in a significant cost savings. Unfortunately, this means that the network must be shared with a host of other applications that consume bandwidth. Also, there is no means for video content to be given higher priority than other types of traffic, which can dramatically increase the difficulty of delivering high-quality, high-bandwidth content in real-time to viewers, as is commonly done on IPTV systems.

Viewed on Consumer PCs

A reasonably powerful PC is capable of running the viewer software required to decompress and display most compressed video formats. Performance can sometimes be improved through the use of graphics accelerator cards or additional memory that is added to the system. In some cases, viewers will watch the content on the display screen of the PC itself; in other cases, the video will be displayed on a television set that is connected to a video output port of the PC.

Other consumer video playback devices have begun to enter the market for Internet Video content. One of the most popular portable video viewers is the Apple Video iPod, which features a screen resolution of 320 × 240 pixels. Most of these portable devices have a limited range of video file types that they will support, so it is essential for the consumer to select only those content files that are compatible with their device's capabilities.

Which Is Best?

In the preceding two sections, we discussed the principal differences between IPTV and Internet Video that we will discuss again in subsequent chapters. Table 2.1 summarizes the key points.

Now that these differences have been explained, the question may arise “How do I choose between them?” For many broadcasters, no choice may be necessary—the broadcaster may simply chose to offer content to viewers using both technologies at the same time.

•   In the case of IPTV networks, there is no real difference to a broadcaster between having a signal carried on a digital CATV or a digital satellite network versus carriage on an IPTV network. In all three cases, broadcasters negotiate a contract with the network provider, and content can be supplied in almost any form that is convenient—over the air, as a digital video feed over a telephone company supplied circuit, as fiber optic connection or whatever format suits both parties. No matter what format is chosen, the IPTV network provider will most likely need to perform some sort of processing on the delivered signal to make it compatible with their network. This can include compressing the signal, changing compression format or many other changes that the broadcaster won't be able to control. Any or all of these tasks will need to be performed by the IPTV provider, just as they need to be performed by digital CATV or satellite providers.

	IPTV	INTERNET VIDEO
Nature of Content	Continuous streams of content	Discrete content segments
Content Selection	Hundreds of programming “channels”	Millions of content files
Content Format	One or two formats selected by provider	Dozens of formats with multiple players
Delivery Networks	Private IP network	Public Internet
Viewing Device	Consumer TV via STB	Consumer PC display or portable device

TABLE 2.1    Key Differences Between IPTV and Internet Video

•   In the case of Internet Video networks, broadcasters will probably be heavily involved in managing which content will be offered to viewers and how it will be offered to viewers. In many cases, this content will be delivered to viewers by means of a Web site that is owned and operated by the broadcaster themselves. However, this will only be suitable for programming where the broadcasters own the appropriate rights. (This will not be that case in many circumstances for programming that is produced by independent production companies or that comes from national network feeds.) One visible result of the ownership limitation in the U.S. are local broadcaster Web sites. These sites heavily feature video clips from local news and weather programs that are produced by the local broadcaster, but they do not include other programming that is purchased from third parties.

Many broadcasters will find that their programming is carried in both ways—as linear feeds over CATV, IPTV and satellite systems, and as discrete content elements over Internet Video services. For popular prime time programming, most local broadcasters won't have the rights to host this content on their local Web sites. Instead, these programs may be available from the Web site of a national broadcast network. The question of who pays for this content will be something that we will take up in the next chapter.

Reality Check

For this chapter's Reality Check, we will discuss a relatively new service that combines some of the attributes of both Internet Video and IPTV delivery mechanisms. This example shows how these categories are already starting to overlap.

MobiTV – Blurring the Lines

An innovative service has been launched to provide standard television network programming to viewers via several different user devices. The service is named MobiTV because of the substantial deployment for mobile telephone users, with more than 1 million reported users in October 2006.¹

MobiTV has introduced service into several different markets:

•   Wireless network suppliers who have chosen a group of phones that can be configured to accept the MobiTV broadcast. For this to work, selected phones can be downloaded with special software that enable the phone to locate the desired data stream so the user can select the content to be viewed.

•   Certain brands of smart telephones (such as Treo and Palm) have the ability to tune to MobiTV on any wireless network. These devices still require proper configuration and a data service from the wireless carrier. In fact, many carriers recommend that their users purchase an unlimited wireless data service to avoid excessive data service charges that might be incurred by viewing video over the networks.

•   PC users with broadband connections, either through wired broadband connections such as DSL or cable modems or through wireless connections such as Wi-Fi, can subscribe to yet another service. One provider of this service, AT&T, is marketing this version of MobiTV under the brand name of “AT&T Broadband TV.”

The mobile/smart telephone versions require a monthly subscription fee for the programming on the order of $10 per month as of this writing in addition to a wireless data plan. The PC version has a fee on the order of $20 per month; PC users must supply their own broadband network connections to the Internet.

AT&T Broadband TV is a hybrid of both IPTV and Internet Video. Here are the ways that the service is like IPTV:

•   The content is provided in a linear broadcast, with no fast-forward, rewind or pause capability.

•   Some channels have commercials; others do not.

•   User interactivity is limited to choosing between different television channels.

•   Channel change speeds are on the order of 1 to 10 seconds, perhaps somewhat slower than some IPTV installations, but quicker than most Internet Video applications.

•   No noticeable buffering time is required when a channel is selected.

Here are the ways that AT&T Broadband TV is like Internet Video:

•   Viewing is done using a standard PC running Windows software and the Adobe Flash player. No television tuner card is required in the PC.

•   Viewers supply their own Internet connection.

•   Video resolution depends on connection speed, with some video significantly below SD resolution.

•   There is a substantial delay on at least some live television channels—we measured some at more than one minute.

As of this writing, MobiTV has raised $125 million in venture capital financing.² Investors included companies such as Adobe Systems, who supply the Flash software used by MobiTV, and Hearst Corporation, a large media company with television stations, newspapers, Internet and other media outlets. Clearly, some large companies are interested in participating as this market evolves.

There is no single, universal definition of what is IPTV and what is Internet Video. What's important is to remember that whenever IPTV comes up in a conversation, one should be careful to qualify what the speaker is talking about before making any conclusions.

Summary

This chapter focused on the differences between IPTV and Internet Video, terms that are often used in very similar contexts by experts. In this book, we will talk about IPTV as a video service that offers multiple channels of programming distributed on a real-time basis to viewers who typically use an STB to watch the content on a television or other display device. We'll talk about Internet Video that consists of thousands or millions of discrete content elements (files) that are viewed on a monitor for a PC.

These differences are important, because they affect the viewer's ability to control when and where specific content is viewed. As we move into the future, these differences will become somewhat less important, as IPTV providers offer more and more content on demand, and as Internet Video providers offer more linear and long-form programming.

 

1. MobiTV press release, October 11, 2006

2. From GigaOmniMedia, Inc. Web site article, gigaom.com/2006/11/01/mobitv-adobe-hearst/, November 1, 2006