HbbTV: New paths for convergence between TV and internet
By Carlos Alberto Martín Edo – Senior Project Engineer at ATOS
Recent years have seen a definite increase in consumption of audiovisual content broadcast over the Internet. According to the report , 80% of Internet traffic will be caused by audiovisual content by 2020 and a significant part of it will be consumed through mobile devices. This new trend has led to the appearance of new so-called OTT (Over the Top) operators, which provide their services over infrastructures deployed by other operators) with great success as they offer catalogues comprising thousands of contents for a modest fixed rate.
Contents broadcast through the Internet may be viewed by means of mobile devices, computers, devices connected to displays and also through the TV screen itself. This has resulted in the paradigm of hybrid TV or connected TV, which is characterized by TV screens that can receive and play content received both from a traditional broadcast network and from the Internet.
There are basically two different models for exploitation of content directly on screens: either the manufacturers of TV sets determine which content will be available or screens may support the HbbTV (Hybrid Broadcast Broadband TV) standard , enabling linear TV operators to exploit their contents.
In the first model, there is a button in the remote control allowing access to the manufacturer’s content portal. In some instances, applications such as those from mobile platforms are available. TV operators have also favoured this solution by developing applications for all major manufacturers of displays. As the content portal is the manufacturer’s own portal, no compatibility standards must be supported and a proprietary specification may be established instead. Traditional TV operators and operators of the new OTT platforms see their development costs soar as they have to launch applications for display manufacturers and models for which compatibility is desired. Additionally, agreements must be entered into with manufacturers to have the relevant application available in their TV sets.
On the other hand, the HbbTV standard is an interoperability technology though out to enable users access contents from any operator by purchasing any supported screen. This model is no longer within the manufacturers’ control (provided that a decision is made to integrate the HbbTV standard in the display and provided also that such support is enabled by default or easy to configure by users), but linear TV operators may directly offer content on the TV screen via Internet. To such purpose, a TV operator broadcasts along with the audiovisual standard a simple graphic application inviting users to access the content portal. This standard specifies that said access must be done through the remote control’s red button and that is why some operators call “Red Button” their HbbTV application. In practice there is even no need to send such graphical interface through the air, just putting it on a server and sending the URL in a signalling table called AIT does the trick as well.
Therefore, the main feature of this model for content exploitation via Internet lies in the fact that TV operators are able to make the screen link to their content portal, which is done by including very light information transmitted over the diffusion channel. Overload in transmission flow is minimal (some tens of kilobits per second) while enabling access to thousands of customized content items.
The TV screen integrates an Internet browser that reads HbbTV contents in a way that is similar to how web browsers for computers work. Although called HbbTV applications, they are actually web contents in a HTML version. The initial versions of this standard would use CE-HTML, that is, a simplified HMTL for easier interpretation in consumer electronics devices, although newer versions support HTML5.
As for contents, there are many types, such as news made up of text and pictures or what the standard terms as digital teletext (which is somewhat paradoxical as teletext in analogue TV is an intrinsically digital system). However, the flagship contents of HbbTV applications are programs already broadcast, thanks to the fact that the standard specifies playback of audiovisual formats.
As already pointed out, this standard has seen different versions released to include new capabilities. Thus, version 1.5 featured the novelty of support for adaptive streaming based on standard MPEG-DASH technology . Adaptive streaming has the distinct feature of allowing several qualities to be available (in terms of encoding binary rate) and the player assesses which is the highest bit rate that may be required in each case in such a way that both user-perceived quality and use of the transmission bandwidth are streamlined. Additionally, DASH allows live streaming, while prior technologies were based on progressive downloading, that is, the downloading of a video file adapted in such a way that playing it as is being received was possible, with no need having the file fully downloaded.
As for version 2.0, a feature worth noting in addition to HTML5 support, is providing for integration with a second screen (companion screens and streams), in such a way that the “main” screen and other “additional” screens will show contents that are related in a coordinated, synchronized fashion. It is a very well-known fact that viewers usually watch TV while operating a mobile device for personal use connected to the Internet. That is why this new version of the standard has seen the opportunity of enriching contents through interaction between the two screens.
This evolution of services offered by operators is yet another sign of the technological convergence process that we have been witnessing for a couple of decades now, which is felt both in receivers and in networks and services, also including multimedia content.
 ATOS. “Accelerating the race to value.” Serie Look Out 2020+; Industry Trends - Telecom. Available in: https://atos.net/content/mini-sites/look-out-2020/assets/pdf/ATOS_LOOK%20OUT_TELCO.pdf
 Carlos Alberto Martín, José Manuel Menéndez and Guillermo Cisneros. “Connected TV: new opportunities for the accessibility”. NEM Summit. Istambul (Turkey). 16-18 October, 2012.