Prototyping BBC News on Vista Media Center
In a comment to our post, Red Button Arcade, we were asked about services on Windows Media Center. Although we have no plans at this time to launch live services, a member of our team has used our One in Ten innovation programme to investigate the technology behind it.
Traditionally, text services like the BBC's Red Button and Ceefax, have always been transmitted as part of the TV signal, and extracted by the hardware at the viewer's end.
But what if we were to make use of the viewer's internet connection for interactive content, even if the viewer was still watching a TV channel that's being broadcast over the airwaves? Are there any technical advantages in doing so, and what new things are made possible by transmitting interactive services over the internet instead of over the broadcast signal?
Last year, I worked on a "One in Ten" innovation project that considered these points. The result was simple application that loaded BBC News content using the viewer's internet connection, and displayed it on top of whatever the viewer was watching. The current top stories are shown and the viewer can read more by selecting a headline.
I chose to target Windows Media Center as it's quite a flexible TV platform from the developer's point of view. Applications are written using the .NET Framework, and it has features that are becoming increasingly widespread on consumer TV hardware, such as a grid EPG and PVR.
One thing we learned was that we instantly lose the tight coupling between interactive service and TV channel, which was previously enforced by technical limitations. So the viewer could now call up the BBC News text service even if they were watching a non-BBC channel, a recorded TV programme, or even a DVD, that had nothing to do with the BBC.
This is an example of an existing tight connection (broadcast channel and interactive service) losing some of its relevance in the IP-delivered world. To make sure our future services make the best use of the technology available, we will need to identify these differences and work with them. In this case, it is clear that branding the text service as a BBC product, becomes more important as the user may not necessarily have arrived from a BBC channel.
Another limitation of traditional text services, is in the amount of content they can carry. All available content was sent to the viewer's machine in a "carousel", and the interactive application loaded the viewer's chosen page when it arrived. This was down to the one-way nature of the broadcast medium.
The IP based model has the clear advantage of two-way communication. So content is only sent to the viewer when they request it. This is a more efficient way of transmitting text content - effectively "narrowcasting" it, instead of broadcasting it.
For the viewer, this means that the interactive services in future, need not be limited in terms of content. One day soon, it should be possible for viewers to access most of the BBC's web content while watching TV!
Shalim Khan is a software engineer in the BBC's TV Platforms Group.