Interactive Television - User Interaction

User Interaction

Interactive TV is often described by clever marketing gurus as "lean back" interaction, as users are typically relaxing in the living room environment with a remote control in one hand. This is a very simplistic definition of interactive television that is less and less descriptive of interactive television services that are in various stages of market introduction. This is in contrast to the similarly slick marketing devised descriptor of personal computer-oriented "lean forward" experience of a keyboard, mouse and monitor. This description is becoming more distracting than useful as video game users, for example, don't lean forward while they are playing video games on their television sets, a precursor to interactive TV. A more useful mechanism for categorizing the differences between PC and TV based user interaction is by measuring the distance the user is from the Device. Typically a TV viewer is "leaning back" in their sofa, using only a Remote Control as a means of interaction. While a PC user is 2 ft or 3 ft (60 or 100 cm) from his high resolution screen using a mouse and keyboard. The demands of distance, and user input devices, requires the application's look and feel to be designed differently. Thus Interactive TV applications are often designed for the "10-foot user interface" while PC applications and web pages are designed for the "3ft user experience". This style of interface design rather than the "lean back or lean forward" model is what truly distinguishes Interactive TV from the web or PC. However even this mechanism is changing because there is at least one web-based service which allows you to watch internet television on a PC with a wireless remote control.

In the case of Two-Screen Solutions Interactive TV, the distinctions of "lean-back" and "lean-forward" interaction become more and more indistinguishable. There has been a growing proclivity to media multitasking, in which multiple media devices are used simultaneously (especially among younger viewers). This has increased interest in two-screen services, and is creating a new level of multitasking in interactive TV. In addition, video is now ubiquitous on the web, so research can now be done to see if there is anything left to the notion of "lean back" "versus" "lean forward" uses of interactive television.

For one-screen services, interactivity is supplied by the manipulation of the API of the particular software installed on a set-top box, referred to as 'middleware' due to its intermediary position in the operating environment. Software programs are broadcast to the set-top box in a 'carousel'.

On UK DTT (Freeview uses ETSI based MHEG-5), and Sky's DTH platform uses ETSI based WTVML in DVB-MHP systems and for OCAP, this is a DSM-CC Object Carousel.

The set-top box can then load and execute the application. In the UK this is typically done by a viewer pressing a "trigger" button on their remote control (e.g. the red button, as in "press red").

Interactive TV Sites have the requirement to deliver interactivity directly from internet servers, and therefore need the set-top box's middleware to support some sort of TV Browser, content translation system or content rendering system. Middleware examples like Liberate are based on a version of HTML/JavaScript and have rendering capabilities built in, while others such as OpenTV and DVB-MHP can load microbrowsers and applications to deliver content from TV Sites. In October 2008, the ITU's J.201 paper on interoperability of TV Sites recommended authoring using ETSI WTVML to achieve interoperability by allowing dynamic TV Site to be automatically translated into various TV dialects of HTML/JavaScript, while maintaining compatibility with middlewares such as MHP and OpenTV via native WTVML microbrowsers.

Typically the distribution system for Standard Definition digital TV is based on the MPEG-2 specification, while High Definition distribution is likely to be based on the MPEG-4 meaning that the delivery of HD often requires a new device or set-top box, which typically are then also able to decode Internet Video via broadband return paths.

Emergent approaches such as the Fango app have utilised mobile apps on smartphones and tablet devices to present viewers with a hybrid experience across multiple devices, rather than requiring dedicated hardware support.