Network Insight Institute

Andrew Cohen

Andrew Cohen, Io research

Datacasting and interactive television can and probably should be examined independently of each other, though not exclusively so. It is worth also looking at that point where, at least in theory, the systems converge, or perhaps more correctly, collide. It is this restricted aspect of the field that I want to look at today: the point where right now the whole theory seems to come slightly unstuck.

There may be someone who would accuse me of overstating some of the hurdles to a true convergence of datacast technology and interactive television - or indeed perhaps worse, of underestimating the viewer's ability to engage sucessfully with increasingly demanding electronic devices and interfaces. I can say from experience though that the ability of users not to read simple instructions on a web page should not be underestimated. And that is only on a PC. I therefore consider the whole issue of graphical user interface design to be critical to any prospect of convergence. I don't think it is fair to say that there is even technical difficulties in convergence. In the main I think the issue of graphic user design has not been adequately handled. From what I have seen internationally, it has certainly not been successful.

I am trying to define datacasting in a very practical way. My definition is in two parts: the first is the wireless broadcasting of data streams, other than real time video and audio, to remote applications; and the second is the wireless broadcasting of data files to remote storage systems. These are practical definitions. From a technical perspective it makes little sense to define datacasting, as the Broadcasting Services Act does, as a super set which includes interactive television. I have specifically excluded real-time video and audio. I think from a technical point of view we should try to distinguish between them, and recognise that television and radio as we know it, and television and audio streams that are associated with TV, are not themselves the datacasting that we are interested in here today.

This definition of datacasting is not a single technology; it is really a model. You can argue quite appropriately that it should include IP multicasting, even over wires, but that opens up a whole can of worms about streaming services, and whether or not they should be regulated under the Broadcasting Act. I will leave that thorny issue for another day. In those definitions wireless itself might be superfluous, but it does reflect reasonably well the prominent distributions of technologies in Australia, and therefore defines the field reasonably neatly.

Real-time data streaming is, if you like, synchronous data or a synchronous service. The distribution of data files to remote storage is an asynchronous service.

My defintion of iTV is 'the wireless broadcasting of data, associated by time or content, with broadcast television services, intended either to control remote hardware, or to provide on-demand displays on a TV screen'. Again, in this instance, wireless may be superfluous, but it does help us to define a field of investigation.

The iTV data might be invisible to the viewer when it makes hardware function calls such as changing tuning, dialling the modem, and triggering the recording device, whether an internal PVR or an external recording device. It may equally be stored interactive TV data and then recalled.

The process of storage and recall, which I will come back to shortly, may be either menu driven or enabled effectively by a video hyperlink. This would enable you to click on something or press a button on your remote control, so that some data would appear which had been stored locally. Alternatively it may be accessed directly by the viewer through an on-screen menu.

I would also define interactive TV data as excluding the use of the TV screen for email. From the technical point of view these are quite distinct services, and I want to stress again that I am giving a purely technical overview. Datacasting is also not a process which lends itself particularly neatly to email or web access; it may be an adjunct to either of those but, in itself does not deliver those services.

Click here to view Andrew Cohen's powerpoint presentation.

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