Category Archives: Digital Terrestrial

The Connected TV Usability Index – coming soon…

The Connected TV blog seems a good place to announce a new venture which farncombe, which hosts this site, is currently working on. This new endeavour involves benchmarking the usability of connected TV devices.

Those of us with access to a connected TV experience – whether on a smart TV, games console, laptop, tablet or set-top box – will all have our favourite bugbears about the connected user experience: the number of clicks it takes to call up a particular piece of on-demand content, over-complex remotes that don’t match what’s on the EPG, screens that are difficult to navigate, etc. etc.

But is it possible to create a standardised set of objective, quantifiable tests with which to assess and compare the user-friendliness of all these different screens?

Well, farncombe thinks it is. Using the knowledge and experience of its engineers at the Farncombe Test Lab in Vauxhall, London (which is already carrying out technical testing on some of our clients’ hybrid receivers), as well as the EPG design knowhow of its user experience practice, WeAreAka, farncombe has worked out a standardised battery of tests that assesses the most common ‘user journeys’ on connected TV devices, the types of feature that improve usability, and the kind of bad UX design practices best avoided.

Over the coming months farncombe will be refining its thinking, testing an initial batch of connected TV devices, and publishing some of the early results as a new industry monitor provisionally dubbed ‘The Connected TV Usability Index’.

The intention is to create a benchmark for viewers and industry alike, by regularly reporting which connected TV devices are ‘best in class’ for a particular usability category – and thereby helping consumers make a more informed choice as they migrate towards this complex emerging market. The first manufacturers are already signed up.

Farncombe believes that manufacturers and operators alike will find the index a valuable tool to help them understand how to enhance the TV viewing user experience.

If you are a connected TV device manufacturer and you believe your user experience is best-in-class, then there is still time for you to be involved at no cost. Please click here to contact us.

If you want to share with us your suggestions about those features you believe should be on our shortlist – and even those which are the most irritating – then we welcome your comments.

Watch this space for more details!

Danish T2-Lite trial goes for all-mobile channel offer

Details have emerged about some of the technology choices adopted for the Copenhagen ‘T2-Lite’ trial, for which Danish operator Open Channel was awarded a licence in August last year.

The trial, which launched on January 1st this year and could run for up to three years, uses UHF channel 39 in Copenhagen, and claims coverage of more than 700,000 households.

In contrast to the BBC R&D trial last year, which squeezed a T2-Lite channel designed for mobile reception into the gaps between a fully-fledged HD service transmitted in standard DVB-T2 mode (now dubbed ‘T2-base’), the Copenhagen trial consists entirely of T2-Lite TV and radio channels carried on up to 16 Physical Layer Pipes (PLPs). As their name suggests, each of these can be regarded as a separate data-pipe with its own bit-rate and robustness characteristics, a notable feature of the second-generation DVB DTT standard.

Open Channel’s calculations show that configured in this manner, a T2-Lite multiplex can match the data-rate offered by a DVB-T one (see table below), yet still offer good mobile reception (unlike DVB-T as generally configured).

Stationary reception DVB-T 20 – 22 Mbit/s DVB-T2 37 – 40 Mbit/s
Mobile reception DVB-H 10 – 13 Mbit/s DVB-T2 Lite 20 – 25 Mbit/s

Source: Open Channel

The difference between the T2-base multiplex data-rate (40.2 Mbit/s in the UK) and that of a T2-Lite mux (20-25 Mbit/s) is explained by the fact that the PLPs within it are configured to be much more robust for mobile reception purposes, so run at lower bit-rates (the DVB-T2 spec sets a maximum of 4MBit/s for PLPs when T2-Lite is used).

But that in turn means that they can easily be captured by fixed aerials, too: in other words, the same channel offer is receivable on either living-room displays fed from a fixed rooftop antenna or handheld devices equipped with a T2-Lite tuner (the DVB predicted last September that soon, all [DVB-] T2 chipsets will support T2 Lite).

These channels will, of course, not be HD quality, but that has to be set against the fact that no separate (expensive) mobile TV network needs to be constructed.

One of the interesting assertions made by Open Channel is that DVB-T2 Lite is not only suitable for mobile TV. It is, the company says, “also highly suitable as the future standard of digital radio in place of DAB & DAB+ [...]. With the DVB-T2 / T2 Lite profile you get 2.7 to 3.7Mbit/s capacity (~ 40 / ~ 55 HE AACv2 radio stations) compared to the DAB / DAB+ 1.1 Mbit/s capacity (~ 6 mpeg1 layer II / ~ 16 HE AACv2 radio stations) with the same propagation model.”

New group formed to promote uptake of MPEG-DASH standard

A new lobby group has been created to drive more widespread adoption of the new MPEG-DASH (Dynamic Adaptive Streaming over HTTP) standard, already adopted by a number of European hybrid platforms, including the UK’s Freeview HD and the French next-generation DTT norm, TNT 2.0. It is also expected to be included in the UK hybrid DTT standard, YouView.

The DASH Promoters Group (DASH-PG) has been created following the ratification of the MPEG-DASH standard in November 2011. The idea behind the standard is to define a universal delivery format for Internet, based on the ‘best elements’ of proprietary streaming technologies such as Adobe Dynamic Streaming for Flash, Apple HTTP Adaptive Streaming and Microsoft Smooth Streaming.

Adaptive streaming is a client-controlled technology which works by adapting, in real-time, to the network bandwidth available for a video-stream without the need for ‘re-buffering’. Thus, if the available bandwidth suddenly reduces, the client drops to a lower resolution by calling on a lower bit-rate stream. This may degrade the picture, but side-steps the problem that the higher bit-rate stream may stutter or freeze while waiting for extra bits to be received. When bandwidth returns to normal, the client automatically switches back to the higher bit-rate stream.

Adaptive bit-rate is regarded as a key technology required to deliver a good quality of experience to consumers accessing OTT video, where the IP network is unmanaged.

The membership of the DASH Promoters Group represents a significant cross section of major players across the multimedia and video delivery value chain. Microsoft, Netflix and Qualcomm are the founding members. Other companies currently include: Adobe, AEG Digital Media, Akamai, BuyDRM, Digital Rapids, Digital TV Labs, Dolby, EBU-UER, Elemental, Envivio, Ericsson, Harmonic, Intertrust, NDS, Packet Ship, Path1, RGB Networks, Samsung, Thomson, University of Klagenfurt and ZiXi.

In addition to promoting broad adoption of DASH, the Promoters Group will focus on aligning ongoing DASH standards development, promoting the use of common profiles across industry organizations, and facilitating interoperability tests and plug-fests to demonstrate the usability and completeness of the DASH standard.

To learn more about the DASH Promoters Group, click here.

 

IBC 2011 – The wall-size interactive display surfaces at NDS

Take a screen as big as a wall linked to a connected TV, open half a dozen of the OTT apps or widgets at once, and enlarge and scatter them around a centrally-displayed video image. In a nutshell, that’s the NDS ‘Surfaces’ concept: an imagined scenario of how future display technologies could be deployed that the technology company believes could be only five years away.

However, the dynamic visual experience this set-up makes available is considerably richer than that thumbnail sketch would suggest. Controlled through a tablet, ambient lighting can be varied, the video display expanded and shrunk, and different sets of widgets called up depending on who’s in the room. In one of the scenarios shown, a family breakfasting could have weather and travel information showing either side of a TV news bulletin ‘screen’, below which a display of contextual headlines (triggered by tags embedded in the news video stream) would continually update.

Other scenarios showed the entire wall being used for an expanded super HD movie viewing (with the lights dimmed), and a talent show invoking social media applications such as Twitter or Facebook around the screen, together with a voting app. One of the key notions involved is the triggering of changes in the display through meta-data in the broadcast stream.

Simon Parnall, UK Vice President Technology at NDS, said one of the motives behind the demonstration was a recognition that more attention needed to be paid to the consumer’s viewing experience. Given the continually expanding screen sizes available, the scenario being presented was not that far-fetched, he suggested.

The wall-sized video ‘surface’ apart, all the technologies used were available today, with the entire demonstration being run through a Google Chrome web browser using the new HTML-5 standard.

 

IBC 2011 – DVB hopeful ‘T2-Lite’ will do better than DVB-H

Europe’s digital TV standards body, DVB, has formally unveiled its new ‘T2 Lite’ profile, designed to provide a subset of the full DVB-T2 specification which is optimised for mobiles and handheld devices.

DVB is hoping it will succeed where the first-generation mobile broadcast standard DVB-H failed, in part because – in the words of chairman Phil Laven – “mobile operators are going to have a serious problem of congestion on their networks” if video consumption on mobile devices continues to increase at current rates.

But Laven also pointed out that the new stripped-down, rugged profile allows the technology to be easily tested in the marketplace, because it can be integrated into a DVB-T2 multiplex without the need to build a dedicated network. This potentially makes its use more cost-effective than DVB-H.

BBC R&D experiments have shown that using a DVB-T2 multiplex normally carrying 40.2MBit/s (as in the UK Freeview HD profile), a T2 Lite channel could be squeezed into a 1.02MBit/s stream, with the DVB-T2 channels taking up the remaining 33.6MBit/s (the loss of 5-6 MBit/s is explained by the extra capacity devoted to making T2 Lite more robust).

Peter Siebert, DVB’s project director, promised that “very soon, all [DVB-] T2 chipsets will support T2 Lite.”