science

Interactive television standards

Interactive television standards is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Interactive television standards rather than just read about it. In short: Interactive television standards are standards for television broadcasting that are designed to add modes of interaction and feedback mechanisms, thereby extending the traditional television experience. History Interactive television was first standardized in the 1980s with Teletext, used in analog television.

Key takeaways

Interactive television standards belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Interactive television standards to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Interactive television standards from memory before moving on to harder problems.

Reference excerpt

History Interactive television was first standardized in the 1980s with Teletext, used in analog television. This standard, which simply added data to invisible scan lines, allowed limited interaction with television sets to visualize extra textual and numerical information, such as show schedules and weather data, as well as optional subtitles. Today, the technology has developed to a point that allows for a more complex, bidirectional communication. Early private broadcasters, such as Canal+, were the first to adopt this new form and have continued to develop it over the years. As the analog format became obsolete, the Digital Terrestrial Television (DTT) project was developed, which digitalized public television, in competition with private broadcasters. Among its new features was interactive menus, which (as in private broadcasting) gave information to the user and allowed them to adapt the product for their own needs. This interaction is possible due to Set-top-Boxes (STBs), television decoders that are able to receive a digital signal, decode it, and display it through an analogue television set. This device allows analog users access to the same content as the digital television net. Running interactive programs is one of the STB's functions, among others. STBs are required to be dynamically programmed and updated, often done by an intermediary software that runs both the applications and the audiovisual signals simultaneously. This intermediary software is referred to as middleware. Some STB systems allow updates via USB flash drives.

Private standards or private property

Media Highway Defined by Canal Plus Technologies, the media highway represents the wide range of middleware solutions that allow the STB software to do the following: interpret and execute interactive applications, broadcast software and data from servers to interactive applications via satellite, cable, and/or terrestrial nets. Other functions also include having different profiles to better respond to the needs of the broadcaster. These interactive applications can be written in different programming languages as Java, MHEG-5 or HTML, and can support the middleware specifications DVB-MHP, OCAP, DAVIC or ATSC, and other specifications.

Open TV Core Open TV Core is the most important product from Open TV, a middleware for digital television (DTV). The Open TV Core software technology contains a hardware abstraction layer (allowing the hardware to be independent), TV libraries (a selection of execution environments for the interactive applications), and support for Personal Video Recorders (PVRs), to create a DTT environment for the decoders (carried out by the STBs). TV libraries include support for Rich Graphics (RG) and High Definition (HD), net communications from a phone line or a broadband internet provider (via DSL, ethernet or fibre), management for the digital audio and video signals (DVB or other standards and formats), and authentication/encryption via CA/DRM systems. Open TV Core supports a number of Applications Environments Execution (AEE) programs, including the 'C' Virtual Machine (an HTML browser), an Adobe Flash presentation environment, and a Java Virtual Machine, in compliance with the MHP standard. The 'C' Virtual Machine is an execution environment that allows the APIs of the Open TV software Developers Kit to create applications in O code, centered on TV by via development tools from Open TV or other sellers.

Open or public standards

MHEG As early as 1995, the ISO (International Organization for Standardization), together with the Multimedia and Hypermedia Experts Group, published the MHEG standard. This gave an approach to the creation of multimedia applications that could work in every operative system in compliance with this standard. Conceptually, MHEG intended to do for multimedia application as HTML did for documents, to give a common exchange format that can be executed by every receiver. MHEG-1: this version included support for objects containing procedure codes. One may add to the basic model of MHEG-1 by adding decision making functions, as it was not possible in any other way. MHEG-3: this version defined a standard virtual machine and a byte representation code, giving it portability through hardware platforms. These versions were unsuccessful because they were based on concepts that the industry was not technologically ready to execute. MHEG-5, a simpler version of MHEG-1, was created in April 1997. While many of the functions were identical, there were many differences between the two versions. MHEG-3 was overshadowed by the success of Java, and in 1998, the ISO created MHEG-6, based on the fifth version but with added support for the use of Java to develop object scripts, combining MHEG with the procedural elements of Java. For this, they defined a Java application programming interface (API) for MHEG, allowing Java to manipulate MHEG objects in its mother application. Though the MHEG-6 was not extended, it was the basis for the DAVIC's (Digital Audio Video Council) standard.

DAVIC This standard was created a little later on after the MHEG-6 in 1998. It was created by adding a new series of APIs for Java to MHEG's sixth version. The APIs of the above-mentioned standard allowed the Java-created objects access to some information services, as well as control of audio and video services, and the management of resources in the receiver. Though the creation of an application was not possible with Java alone for the receiver DAVIC, the Java APIs were already capable of controlling more elements in the receiver than what was possible with other standards.

DVB-MHP (The Multimedia Home Platform) This was defined by the Digital Video Broadcasting (DVB) to offer interactive services in digital television (DTV). It is a limited version of the Java virtual machine, where a set of extra functionalities are added to make adjustments to the DTV environment. To arrange this standard's specifications, there are three definable profiles, all relating to the capabilities of the STBs:

… excerpt ends here. Continue reading the full article.

Worked examples

Example 1 — a first encounter with Interactive television standards

Start with the simplest possible case. Write down what Interactive television standards claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Interactive television standards before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Interactive television standards ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Interactive television standards

In research: Interactive television standards appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Interactive television standards in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Interactive television standards is common in secondary-school and first-year university syllabi. It links to neighbouring topics Interactive television, Lists of standards, Television transmission standards, so understanding it makes those chapters shorter.
In everyday life: Look for Interactive television standards outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Interactive television standards in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Interactive television standards means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Interactive television standards out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Interactive television standards in simple terms?

Interactive television standards are standards for television broadcasting that are designed to add modes of interaction and feedback mechanisms, thereby extending the traditional television experience. History Interactive television was first standardized in the 1980s with Teletext, used in analog…

Why does Interactive television standards matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Interactive television standards?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Interactive television standards.