HbbTV is now odds on to emerge from the cluster of interactive and hybrid TV standards to become the dominant platform uniting broadcast and connected TV.
Currently sweeping through continental Europe, and under trial in a number of other major countries including China, Japan and the U.S., it looks like the winning hybrid TV platform is emerging, partly through not being too ambitious and sticking clearly within defined boundaries. It leaves plenty of scope for apps vendors, broadcasters and pay TV operators to innovate around the platform and stamp their own distinctive flavor on their products or standards.
The closest to an actual HbbTV deployment outside Europe is in South Korea, where national broadcaster KBS is launching services based on the country’s OHTV (Open Hybrid Television), which is a separate development but almost identical technically and now likely to be aligned completely with HbbTV given its momentum in other countries. In Korea, the service is hybrid digital terrestrial and broadband, as is the case with many early HbbTV deployments in Europe.
HbbTV evolved in 2009 as a joint project between France and Germany, and it is those two countries along with Spain and the Netherlands that have made the early running with HbbTV deployments. In Germany, at least eight broadcasters, including public service broadcaster RTL and pan European media distributor ZDF, are now offering HbbTV apps over terrestrial or satellite networks.
Such apps can combine multiple delivery channels into one coherent service, or provide additional viewing options within a single channel. An example of the first of these use cases is German home shopping channel QVC, which is exploiting HbbTV to unite its various existing distribution channels including TV, Internet and mobile networks, within one coherent service allowing customers to search for products. An example of the second is German private broadcaster Vox, part of the RTL Group, which is using HbbTV for a cooking channel, allowing viewers to access different recipes for demonstration within a show by pressing the “red button.”
In France, public broadcaster France Télévisions has been leading the way and is using HbbTV to expand coverage of the French Open tennis tournament over the next two weeks. It will allow viewers to choose from a number of matches at a given time, again using red button functionality.
Spain, meanwhile, has agreed to adopt HbbTV as its system for connected TV, with pilots completed by broadcaster Mediaset España and Telco Telefonica. These involved Mediaset’s Telecinco importing content from Telefónica’s services, including Movistar Imagenio, Movistar Videoclub and Terra TV.
Similarly, Dutch broadcasters, including SBS, NPO and RTL, have agreed to use HbbTV as their standard for hybrid connectivity, while launches have just occurred or are imminent in Switzerland, Austria, the Czech Republic and Poland.
HbbTV has also won over the Nordic region, which originally was planning to build hybrid broadcast around the alternative Multimedia Home Platform (MHP) developed by the DVB, with the main original difference being that HbbTV is based on HTML while MHP is written in Java language. Germany originally went with MHP, but it failed miserably, partly because there was then little demand for interactive TV in the country.
Now, the Nordic region comprising Denmark, Finland, Iceland, Norway and Sweden, oddly also including Ireland, has replaced DVB-MHP with HbbTV as the common API for hybrid digital receivers within its NorDig digital TV specification. The stated reason is that HbbTV now has much wide market acceptance, with a range of TV applications and new hybrid services, and crucially HbbTV compatible receivers from a number of manufacturers such as Humax of South Korea. Also significant is that HbbTV software stacks are now incorporated in leading hybrid chip sets from Broadcom and Sigma Designs. Most major players in the connected TV arena are now members of the HbbTV Forum.
The success of HbbTV can be put down to three factors: its flexibility; foundation on existing standards that are being implemented anyway as part of OTT and IPTV deployments; and support from industry groups, notably the European Broadcast Union (EBU), whose influence extends outside the continent.
The EBU is hoping that the Olympics will give HbbTV a big lift, and has laid the ground by offering “white-label” HbbTV applications free of charge to its members. These apps are currently being customized and rebranded for deployment just ahead of the games, when they will deliver interactive services to peak audiences during the Olympics.
Equally crucial is the approval of the Open IPTV Forum (OIPF), which has emerged as the major body forging standards for OTT and general online video service delivery over unmanaged infrastructures, as well as IPTV within closed ‘walled garden’ networks.
The key component for OTT that has been adopted by HbbTV is the OIPF’s Open Internet Profile, based on its Declarative Application Environment (DAE), which is a browser for TVs with support for various presentation mechanisms including HTML4, HTML5, SVG, and CE-HTML.
The OIPF specification includes a mechanism for adaptive delivery of MPEG-2 transport streams over HTTP, and this has been incorporated into one of the profiles of the newly just published ISO DASH specifications, according to Mitra. DASH is likely to become the standard mechanism for adaptive streaming, taking over from existing proprietary systems such as Microsoft Smooth Streaming, and possibly Apple’s HLS (HTTP Live Streaming).
Support for DASH streaming was an addition to HbbTV. But, at the outset, it had the right foundation by being built on two relevant and mature technology sets, one being web standards already included in web browsers for embedded devices, and the second being the Digital Storage Media Command and Control (DSM CC) specification already part of the MHEG-5 interactive platform adopted in several countries, including the UK and Australia.
Use of existing web standards provided the basis for broadband access, while DSM CC specified a common approach for interactive services uniting two way online delivery with one way broadcast. DSM CC, therefore, delivered the hybrid component, and although it is a complex set of technologies the basic principle is simple. The aim is to facilitate control over transport of audio and video streams within interactive services in both a bi-directional environment such as a cable TV or VOD system, and also a uni-directional service such as satellite or digital terrestrial.
The challenge was how to simulate interactivity in a one-way environment when there was no return path. The simple answer was to adopt a carousel approach — hence the name. As the receiver in a traditional broadcast environment has no return path and so cannot request specific files from a server, DSM CC periodically transmits every file, and the receiver then grabs the ones it wants as they pass by on the carousel. Of course, this is not particularly efficient since if a receiver misses a file it has to wait for it come round again. But, techniques have been developed and embodied in HbbTV to improve the interactive performance for one way broadcast services.
It will become clear during the rest of 2012 how well HbbTV does perform in a variety of hybrid environments including those involving one-way broadcast, with the Olympics providing useful feedback. But, HbbTV has still not convinced all its doubters, even in Europe. Italy is the notable outsider, having gone its own way by deploying MHP for hybrid services.
The UK is the other major odd one out, since its much delayed connected TV platform, YouView, took a different approach. However, the UK is itself a bit of a hybrid, since the Digital Technology Group (DTG) responsible for digital TV and particularly terrestrial standards in the UK developed an extension to MHEG-5 called the MHEG-5 Interaction Channel (MHEG-IC), allowing broadcast interactive services to be delivered via an IP connection. This made it more like HbbTV, and, subsequently, the DTG has fully endorsed HbbTV for Freeview DTT.