The demise of the digital TV network ITV Digital and the slow take-up of digital audio services may not prove such a disaster, after all. In fact, it may pave the way for new, and more popular, data-based services using existing digital TV and radio technologies.
"Datacasting", as the technology is known, is not a new concept. Digital satellite viewers have been able to receive broadband internet applications for some time, and some basic text-based data services are already available to homes equipped with the latest DAB (digital audio broadcasting) devices. But thanks to advances in chip manufacturing, the possibilities of receiving high-speed datacast services via mobile products, such as personal digital assistants (PDAs), are now beginning to emerge.
Last year, the DAB manufacturer Roke Manor unveiled a DAB tuner about half the size of a mobile phone. And showing last month at the Frankfurt High End Hi-Fi Show was a portable DAB product from Imagination Technologies about the size of a matchbox. Although both devices are intended primarily for audio purposes, both companies are looking to build the technology into PDA devices. Imagination Technologies has been working with the Cambridge-based company TTP Communications and Digital One's commercial digital radio network on a prototype PDA. DAB customers can receive these services with Psion's Wavefinder, a PC-based digital audio tuner.
Matt Honey, managing director of Unique Interactive which makes similar products, says: "We see the mobile space as the key for data services over DAB. Within the next two years, we imagine that people will be using a PDA with a built-in DAB module to access a wide range of data services on the move." So is DAB a potential rival for 3G technology? Not really. Unlike 3G, DAB does not require a new infrastructure of transmitters. It also offers reasonably fast downstream speeds (typically between 200kbps and 250kbps). And, importantly, because bandwidth isn't shared, there isn't the likelihood of much lower access speeds as with 3G. "Telcos are realising that DAB provides a useful way of realising services that 3G won't be able to," says Howard Quentin, chief executive of Digital One, whose products are expected include many of those that 3G is promising, such as internet access and short video clips.
However, because the technology only operates in one direction (from the datacaster to the end user), it needs to be partnered with a return path technology such as GPRS or 3G for interactive applications. According to Keith Hayler, chairman of IP Datacasting Forum, 3G and DAB are natural bedfellows. "DAB offers operators enormous bandwidth within the broadcasting environment."
On trial in the Isle of Man are a number of hybrid DAB/3G applications, including one that uses both technologies for internet connectivity and another that provides a music jukebox to users via a notebook com puter. Developed by Virgin Radio and Scottish Media Group, this allows users to select a playlist using a 3G connection on their computer and to download tracks using a built-in Digital Video Broadcasting (DVB) tuner inside their PC. Nor is DAB the only technology the IP Datacasting Forum is considering for high-speed data delivery. DVB may also provide a complementary service to 3G.
In trials across Oxford recently, NTL Broadcast demonstrated that the existing digital terrestrial network - the same platform used until recently by ITV Digital - could be used for transmit ting both video and data services to a mobile screen fitted inside a car with a 10cm antenna on the roof. Meanwhile, the Finnish company Nokia recently demonstrated a prototype hybrid device that combines a 9210 Communicator mobile phone with a built-in DTT (digital terrestrial TV) tuner.
Unfortunately, whether products such as these come to market lies partly in the hands of regulators. Under current UK legislation, only 10% of digital terrestrial TV spectrum and 20% of digital audio frequencies can be used for data purposes. We could be in for a long wait before datacasting really takes off.
