Interactive television
Interactive television describes any number of efforts to allow viewers to interact with
television content as they view. It is sometime called interactive TV, iTV, idTV or ITV (not to be confused with the British network).
To be truly Interactive, the viewer must be able to alter the viewing experience (eg choose which angle to watch a football match), or return information to the broadcaster.This "
return path" or "
back channel" can be by telephone, mobile SMS (text messages), or cable. Cable viewers receive their programs via a cable, and in the integrated cable return path enabled platforms, they use the same cable as a return path.
Satellite viewers (mostly) return information to the broadcaster via their regular telephone lines. They are charged for this service on their regular telephone bill.Interactive TV can also be delivered via a terrestrial aerial (digital terrestrial TV such as '
Freeview' in the UK). In this case, there is often no 'return path' as such - so data cannot be sent back to the broadcaster (so you could not, for instance, vote on a TV show, or order a product sample) . However, interactivity is still possible as there is still the opportunity to interact with an application which is broadcast and downloaded to the set-top box (so you could still choose camera angles, play games etc).
The term "interactive television" is used to refer to a variety of rather different kinds of interactivity (both as to usage and as to technology), and this can lead to considerable misunderstanding. At least three very different levels are important:
Interactivity with a TV set
The simplest,
Interactivity with a TV set is the one that is already very successful. This got its first big jump with the use of the remote control to enable channel surfing behaviors, and has evolved to include
video-on-demand,
VCR-like pause, rewind, and fast forward, and
DVRs, commercial skipping and the like. It does not change any content or its inherent linearity, only how we control the viewing of that content. This is a kind of interactive TV, and not insignificant, but it is not what is meant in any full sense of the term.
Interactivity with TV program content
In its deepest sense,
Interactivity with TV program content is the one that is "interactive TV", but it is also the most challenging to produce. This is the idea that the program, itself, might change based on viewer input. Advanced forms, which still have uncertain prospect for becoming mainstream, include dramas where viewers get to choose plot details and endings. Simpler forms, which are enjoying some success, include programs that directly incorporate polls, questions, comments, and other forms of (virtual) audience response back into the show. There is much debate as to how effective and popular this kind of truly interactive TV can be. It seems likely that some forms of it will be popular, but that viewing of pre-defined content, with a scripted narrative arc, will remain a major part of the TV experience indefinitely.
Interactivity with content that is related to what is on TV
The least understood,
Interactivity with TV related content or "coactivity", may have most promise to radically alter how we watch TV over the next decade. Examples include getting more information about what is on the TV, whether sports, movies, news, or the like. Similar (and most likely to pay the bills), is getting more information about what is being advertised, along with the ability to buy it but there is currently little or no automated support for relating that secondary interaction to what is on the TV compared to other forms of interactive TV.
Many think of interactive TV primarily in terms of "one-screen" forms that involve interaction on the TV screen, using the remote control, but there is another significant form of interactive TV that makes use of "two-screens." In this case, the second screen may be a PC that is connected to a Web site application that is synchronized with the TV broadcast, but other two-screen forms can involve interaction with mobile phone applications that run in synch with the show or applications on PDAs. Such services are sometimes called "
Enhanced TV" or ETV, but this term is not being used widely anymore as it is seen as anachronistic and is often still misused occasionally. (Note: Enhanced TV originated in the mid-late 1990's as a term that some hoped would replace the umbrella term of "interactive TV" due to the negative associations "interactive TV" carried with it because of the way companies and the news media over-hyped its potential in the early 90's.) Notable two-screen services have been offered for specific popular programs by many US broadcast
TV networks. One-screen interactive TV generally requires special support in the
set-top box, but two-screen ETV services generally do not, relying instead on
Internet or mobile phone servers to coordinate with the TV.
Interactive TV is often described as "lean back" interaction, as users are typically relaxing in the living room environment with a remote control in one hand. This is in contrast to the
personal computer-oriented "lean forward" experience of a
keyboard,
mouse and
monitor. In the case of "two-screen" Interactive TV, however, there may be a mix of "lean-back" and "lean-forward" interaction. 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 known as "
coactive TV."
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), 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').
Typically the distribution system is based on the
MPEG-2 specification.
* Examples of commonly-found middlewares include:
**
DVB-MHP (
Java) - Global standard widely deployed in Europe and Asia
**
OCAP (Java) - US cable industry standard based on
DVB-MHP**
BD-J (Java) - Interactivity layer for
Blu-ray Disc based on
DVB-MHP**
OpenTV (
ANSI C) - BSkyB, UPC, Viasat, TPS
**
Mediahighway (Java,
MHEG-5,
Pantalk) - UK terrestrial, Canal+
**
Liberate (
HTML/
JavaScript) - NTL, Telewest
**
ICTV (
HTML/
JavaScript) - NTL, VNL
**
MHEG-5 (used in UK DTT)
**
Alcatel Open Media Suite - Sasktel, BBTV, Kingston
**
Microsoft TV (
XHTML)
**
BML - Standard used on ISDB platforms in Japan
Development of applications using these technologies is traditionally drawn out due to the limitations of the set-top box, the large amount of testing required and the lack of standardisation of deployed units. Almost all are proprietary and subject to heavy licensing restrictions.
Some interactive television projects are consumer electronics boxes which provide set-top interactivity, while other projects are supplied by the cable television companies (or multiple system operator, or MSO) as a system-wide solution. Some examples of interactive television include:
* MSO systems
**
Time Warner (US)
**
Comcast (US)
**
Cablevision (US)
* MSO trials or demos
**
Full Service Network from Time Warner (US)
* Consumer electronics solutions
**
TiVo**
ReplayTV**
UltimateTV** Microsoft
Windows XP Media Center* "Two-screen" or "enhanced TV" solutions
** See
Enhanced TV for examples
*
Digital television*
Set-top box (
STB)
*
Enhanced TV*
Internet television*
The Enhanced Television Cookbook: PBS's (US Public Television) Interactive Television How to
