We knew when a second national Digital Audio Broadcast (DAB) radio license was put up for grabs in the UK, that it would attract interest, especially given the technology’s capability to also offer mobile TV services from the same network using T-DMB.
And this week UK regulator Ofcom said that it has two bids, one from the company that operates both the national DVB-T television network and the other DAB system, National Grid Wireless, and one from a combination of companies that clearly want to take radio straight to mobiles. Ofcom advertised the second national digital multiplex license back in December.
National Grid Wireless is a buy out from the UK arm of Crown Castle, itself in the process of being sold this week (see separate story) which has in the past absorbed the BBCs home broadcast transmission division. Its parent company is the National Grid, the backbone of electricity carriage throughout the country, and today operates 17 TV and radio broadcast networks.
But it is the other bid that is the surprise and the most intriguing, because it could represent a new force in UK broadcasting. The players include Channel 4, BSkyB, Carphone Warehouse, the UK’s biggest handset retailer, and publisher Emap as well as the smaller UTV Radio, UBC Media and Chrysalis, a radio and music company. Collectively this group is called 4 Digital Group, and says it will launch 10 new national digital radio stations.
Channel 4 Radio would operate three national digital stations: one aimed at 15-to-29 year-olds; one on current affairs; and an all-music station. The other stations would include: Talk Radio from Ulster Television, a music station from Emap, and Sky News Radio, a joint venture between BSkyB and Chrysalis, a 24-hour news channel.
The new 4 Digital Group says that it will work with the Carphone Warehouse to develop digital audio chips to be built into the next generation of mobile phones. Presumably the new DAB network will use DAB 2.0, a new version of the digital radio platform that is not backwards compatible with DAB 1.0, but which will be less of a drain on mobile batteries.
DAB was originally launched using MPEG 1 layer 2 for audio, but this is seen as not a suitable way of delivering audio for TV, so where T-DMB the mobile TV extension of DAB is used for mobile TV, DAB has used the much improved HE-AAC codec also called AAC+ and video is encoded using H.264.
That has led to a recasting of the standard with DAB 2.0 in November 2006, with WorldDAB (now renamed WorldDMB) announcing the adoption of AAC+ and setting up the situation that where countries that have already embraced DAB, all the existing receivers will be incompatible with the new DAB standard. New receivers will become available in Spring this year.
Another issue in the past has been that the power levels required for T-DMB chips (DAB chips) were designed for discreet consumer electronics radio receivers, which either have access to mains power or to larger batteries than mobile handsets and other portable players, and so the chipsets were never really built to offer long term battery life. This was because DAB has not been issued in a Timesliced manner like DVB-H or MediaFLO.
The next generation of DAB 2 chips will be far more energy efficient (older DAB chips use around 250 mW of power all the time instead of bursting to this level for around 7% of the time).
Also most countries have built their DAB networks for in-car coverage, and not always for indoor coverage, so it will be important for this new network to change the way it builds the network in order to ensure that handsets within buildings can receive strong signals. Ofcom said the winning bid would be revealed by July.