Interactive TV Standards

A Guide to MHP, OCAP, and JavaTV

Steven Morris, Anthony Smith-Chaigneau

• Publisher: Routledge
• Year: 2012
• Print ISBN:
  9781138375956
  9780240806662
• Edition: 1
• eBook ISBN:
  9781136035692
• Topic: Languages & Linguistics
• Subtopic: Communication Studies
• Index: Languages & Linguistics

For any digital TV developer or manager, the maze of standards and specifications related to MHP and OCAP is daunting-you have to patch together pieces from several standards to gather all the necessary knowledge you need to compete worldwide. The standards themselves can be confusing, and contain many inconsistencies and missing pieces. Interactive TV Standards provides a guide for actually deploying these technologies for a broadcaster or product and application developer. Understanding what the APIs do is essential for your job, but understanding how the APIs work and how they relate to each other at a deeper level helps you do it better, faster and easier. Learn how to spot when something that looks like a good solution to a problem really isn't. Understand how the many standards that make up MHP fit together, and implement them effectively and quickly. Two DVB insiders teach you which elements of the standards that are needed for digital TV, highlight those elements that are not needed, and explain the special requirements that MHP places on implementations of these standards. Once you've mastered the basics, you will learn how to develop products for US, European, and Asian markets--saving time and money. By detailing how a team can develop products for both the OCAP and MHP markets, Interactive TV Standards teaches you how to to leverage your experience with one of these standards into the skills and knowledge needed to work with the critical, related standards. Does the team developing a receiver have all the knowledge they need to succeed, or have they missed important information in an apparently unrelated standard? Does an application developer really know how to write a reliable piece of software that runs on any MHP or OCAP receiver? Does the broadcaster understand the business and technical issues well enough to deploy MHP successfully, or will their project fail? Increase your chances of success the first time with Interactive TV Standards.

1 The Middleware Market

The introduction of digital TV (DTV) and interactive TV (ITV) is causing huge changes in the television industry. This chapter provides an overview of the current state of the market and examines how open standards for middleware fit into the picture. We will look at the history behind those standards, and take a look at the bodies behind the standards we discuss in this book.

The broadcasting and television industries are in a state of flux on many fronts. The industry has been working toward wooing consumers from a passive role to a more active one, and multimedia and the convergence of the consumer electronics and personal computer worlds play a big part in this change.

The concept of ITV is not new. It commenced with teletext in the 1980s, and unknown to many Warner-Qube was deploying a form of video-on-demand (VOD) in the United States as early as the 1970s. Unfortunately, many of these early attempts were soon shelved due to the cost of having to bring two-way networks into people’s homes. Since then, changes in technology and in the markets themselves have made this possible, and broadcasters are looking to differentiate and capitalize on these new technologies, adding new functionality in order to bring a much more active TV experience to consumers.

Proprietary middleware solutions have been available for several years from companies such as OpenTV, NDS, Canal+, PowerTV, and Microsoft, but we are now in an emerging market for middleware based on open standards. The Digital Video Broadcast (DVB) Project’s Multimedia Home Platform (MHP) is currently leading the development of this market, with the OpenCable Application Platform (OCAP) and Advanced Common Application Platform (ACAP) standards two to three years behind.

MHP saw Finland go first, with initial deployments starting in 2002. Premiere was to be next, the satellite pay-TV operator fulfilling a German dream with the launch of MHP over satellite to about a million homes. This did not happen for a variety of reasons, although since then many other German broadcasters (such as ARD, RTL, and ZDF) have launched MHP services on both terrestrial and satellite networks. Italy has taken a different approach to DTV migration, and the government has assisted the market by sponsoring the introduction of terrestrial MHP set-top boxes. In Italy, we now have a market of 20 million households that is completely serious about launching MHP terrestrial services. Other countries, especially Austria and Spain, look likely to follow: they are among many countries and network operators presently running trials using MHP.

The growth of these open middleware standards raises many questions for the industry as a whole, and in this book we hope to answer some of those questions. In this chapter, we concentrate on a basic overview of the current ITV landscape, looking at where these standards came from, why they are useful, and how they are changing the industry.

Why Do We Need Open Standards?

We are all exposed, at some time or another in our daily lives, to standards. From reading e-mail over the Internet at work to watching television in the evening, a wide variety of standards exist in daily use. These standards are typically defined through a standardization body.

Consumers in general do not involve themselves in any of the fine details, worrying mainly about usability instead. Customers are happy if a standard does the job it was made for. If it represents something cool and funky, that is even better, especially in today’s high-tech culture. From the customer’s perspective, the only concern regarding standards is that they should allow the equipment they purchase to perform “just like it says on the box.”

On the other hand, standards are of great concern to industry specialists, who bring together various technologies to create new products. Open standards are used because they guarantee that compliant systems will be able to work together, no matter which manufacturer actually provides the equipment. Specialists do not always fully agree on the content of standards, of course, as you will see in this book. There are many instances of competing standards in all technology markets, including the fields of broadcasting and ITV middleware.

Until 2002, DVB specifications concentrated on digital broadcasting and associated technologies. Convergence has led to products that use a mélange of previously unrelated standards, and the work of standards bodies such as DVB is becoming more complex in order to keep control of the technology used in these new devices. DVB offers its specifications for standardization by the relevant international bodies such as the EBU/ETSI/CENELEC Joint Technical Committee and the International Telecommunication Union (ITU-R or ITU-T).

For standards such as MHP, the final documentation for the specification includes such things as commercial requirements, technical guidelines, implementation guidelines, and the technical specification itself. This provides companies with all of the information they need to implement the specification in a consistent way, and many of these documents are available over the Internet either free of charge or for a nominal fee.

Furthermore, specification bodies such as DVB and CableLabs also define a certification (compliance) process. For DVB, this is a self-certification process that includes a process for registering compliant products and that may include payment programs that provide access to test suites and possibly branding for implementations such as permission to use the MHP logo. CableLabs offers a Wave certification program, for which costs are not insignificant. We are still awaiting the definition of the OCAP certification process, and it may well be that this will follow a model similar to that of the DVB self-certification process. A more thorough discussion of the MHP self-certification process can be found in Chapter 19.

From experience in the wider open standards world, we know that standards create a fully competitive and open market, where technologies become more widely implemented because they are available to all players in the industry under the same terms. Standards work!

Driving Forces Behind Open Standard Middleware

In the early days of television, several competing technologies emerged for carrying picture and sound information from the transmitter into viewers’ homes. Following many tests and political arguments, three main standards emerged: NTSC, PAL, and SECAM. The fragmentation of the world’s television services among these three standards created a complicated scenario for consumer electronics manufacturers, particularly because each standard had a number of variants. This was most evident in Europe, where neighboring countries chose differing variants of PAL or SECAM, leading to a number of market problems such as receivers purchased in one country not necessarily working in another. To illustrate the problems this caused, Brazil chose the PAL-M system for its TV broadcasts, thus isolating itself from the rest of the world and shutting the door to TV import/export opportunities (except perhaps for Laos, the only other PAL-M country).

Standards in DTV

It would have made sense not to replicate this fragmentation in the move to digital, in that the technology was available to unify the digital broadcasting world. However, learning from experience is not always something people are good at. It would have been obvious that by introducing common digital broadcasting systems consumer electronics manufacturers and ultimately their customers would have benefited from massive economies of scale, but this did not happen. There is still fragmentation in the DTV broadcast market—some say on a much-reduced scale, whereas other commentators disagree. Commercial and political issues, as well as the NIH (“not invented here”) syndrome created the following competing DTV standards.

• Europe chose the transmission technology COFDM (coded orthogonal frequency division multiplexing) for terrestrial broadcasts, adopting this in the DVB-T (DVB-Terrestrial) specification.

• The United States’ ATSC (Advanced Television Systems Committee) chose a system using 8-VSB (vestigial sideband) technology for terrestrial transmission. Canada and South Korea adopted the same system.

• Japan looked at COFDM and the Japanese Digital Broadcasting Experts Group (DIBEG) and then created its own flavor, which included time interleaving, calling it ISDB-T (Integrated Services Digital Broadcasting, Terrestrial).

• Most cable operators use QAM (quadrature amplitude modulation) as the modulation technology for cable systems, although different systems use different transmission parameters and are not always compatible. DVB defined the DVB-C (DVB-Cable) standard, whereas CableLabs defined the OpenCable standard.

• Most satellite operators use QPSK (quadrature phase-shift keying) modulation, although again there are several flavors. DVB defined the DVB-S (DVB-Satellite) standard for satellite broadcasting, whereas the ATSC defined the A/80 and A/81 satellite broadcasting standards for use in North America.

• Brazil recently decided, as has China, it would favor producing alternative “home-grown” broadcasting standards in order to avoid any intellectual property issues outside the country.

As well as choosing different modulation systems, Europe, the United States, and Japan all chose different standards for the service information needed to decode DTV services and for data broadcasting. When these choices are coupled with the continuing use of PAL, NTSC, and SECAM, there are now even more differences among the countries, although some of these are more superficial than others.

Correcting the Fragmented ITV Market

As DTV systems were deployed, network operators wanted to exploit the strengths of these new technologies to provide new revenue streams. This led to an interest in interactive services, which in turn led to a desire for middleware platforms that would enable interactive applications to run on various hardware platforms. Proprietary middleware solutions were by far the most common, with OpenTV, Liberate, NDS, Microsoft, and Canal+ Technologies being among the leading players. Naturally, the services and applications running on proprietary middleware were tightly linked to those platforms, and because operators normally chose different middleware and conditional access technologies this led to the development of vertical markets, the trend away from which is indicated in Figure 1.1.

In a vertical market, the network operator controls the specification of the set-top boxes used on that network and of the applications that run on it. This meant that in a vertical market the set-top box often became the largest financial burden to a network operator, in that the network operator purchases the receiver directly from the set-top box supplier and leases it or gives it away to the viewer as part of a subscription.

With the growth of ITV, television standards bodies around the world decided to create open standards for the middleware needed to run these services. Because these were developed by the same bodies that produced the other DTV standards, the United States, Europe, and Japan all produced different standards for middleware, designed to work with their own service information and data broadcasting standards. These standards are outlined in the following.

Figure 1.1. The digital TV market is currently migrating from proprietary middleware solutions in vertical markets to open standards in horizontal markets.

• Through DVB, Europe created specifications for all types of DTV networks (DVB-T for terrestrial, DVB-C for cable, and DVB-S for satellite). The common features of these systems led to the development of a common middleware standard (MHP) for all three types of networks.

• ATSC, the standards body for the United States, developed the DASE (Digital TV Applications Software Environment) middleware system based on its DTV standards. This has since been used as the basis for the next-generation ACAP standard. Canada and Korea have also adopted ATSC standards, including ACAP, for their terrestrial transmission services. Cable systems in the United States were largely standardized through CableLabs, which modified the ATSC standards for service information in order to make them more suitable for a cable environment. CableLabs developed the OCAP middleware standard, which has a number of features specific to U.S. cable networks.

• The Japanese DIBEG created the BML (Broadcast Markup Language) markup language for ITV. There are no known users of this system outside Japan, and the Japanese standards body ARIB (Association of Radio Industries and Businesses) is currently developing a more advanced middleware standard that is closer to MHP.

• En route to selection of an open standard, Brazil and the People’s Republic of China decided to produce alternative home-grown broadcasting standards for terrestrial transmissions that could lead to yet another challenge for middleware standardization and GEM (Globally Executable MHP).

This is not the end of the story, however. Brazil, China, and Japan all use DVB-C for cable services, and some U.S. satellite operators use the DVB-S standard. According to one middleware supplier, they have already deployed MHP services in China’s Shenzhen province. Due to the mix of different transmission systems selected, Korea is the most complicated scenario of all, where OCAP has been chosen for cable networks, MHP for satellite networks, and ACAP for terrestrial networks.

A few open middleware standards were developed before MHP, and these are in use in a small number of public networks (such as for digital terrestrial services in the United Kingdom). Unfortunately, the size of the markets and competition from subscription-based services (which can offer better content) have meant that these markets have not grown very quickly. At the same time, the current crop of middleware standards is a successor to these standards on a technical level and a commercial level, and in later chapters we will see how MHP and OCAP have taken elements from these standards and applied them in regard to the current conditions in the market.

This profusion of middleware standards has had an impact on the market, fragmenting it further so that different operators may deploy different middleware solutions (either proprietary or open) and different transmission standards. Unless the industry as a whole is very careful about how these standards are adopted and used, this level of fragmentation can only introduce more problems for the entire industry.

By painting such a gloomy picture of the current state of digital broadcasting, some people may accuse us of reinforcing the fear, uncertainty, and doubt that have sometimes been spread by opponents of open standards. We need to highlight these effects in order to understand the consequences of these choices, but the overall picture is really not as bad as we may have made it sound. What we have to remember is that despite the differing digital transmission standards the TV market is traditionally a fully horizontal market. Many people forget this in the DTV debate. Televisions and “free-to-air” set-top boxes are available in retail stores across all countries that have made the move to public digital broadcasting, and consumers have the choice of a range of products from low-end set-top boxes to high-end integrated TVs. Open standards for middleware were created to help fix the fragmentation of the ITV market, and these standards are now being taken up around the world.

What Are DVB and CableLabs?

Before we can look at the standards themselves in any detail, we need a clear understanding of the organizations involved. Many groups in the world are developing standards for DTV. Some of these (such as DVB, ATSC, and the ITU) may be familiar to you, whereas others may be less familiar to some readers. A number of bodies have been involved in the development of the middleware standards we will discuss further, but two main organizations have really driven the ...

Table of contents

• Cover
• Halftitle
• Title
• Copyright
• Contents
• Introduction
• 1 The Middleware Market
• 2 An Introduction to Digital TV
• 3 Middleware Architecture
• 4 Applications and Application Management
• 5 The JavaTV Service Model
• 6 Resource Management Issues
• 7 Graphics APIs
• 8 Basic MPEG Concepts in MHP and OCAP
• 9 Reading Service Information
• 10 Section Filtering
• 11 Media Control
• 12 DSM-CC and Broadcast File Systems
• 13 Security in MHP and OCAP
• 14 Communicating with Other Xlets
• 15 Building Applications with HTML
• 16 MHP 1.1
• 17 Advanced Topics
• 18 Building a Common Middleware Platform
• 19 Deploying MHP and OCAP
• Appendix A: DVB Service Information
• Appendix B: ATSC Service Information
• Index