Monday 5 August 2013

At last - a possibler digital transmission route for smaller stations?

It looks like we might get "DAB Lite" after all. I'm pleased to see that Ofcom has today reported favourably on a DAB experiment which was set up in Brighton between September last year and this January.

It specifically used low-cost low-power techniques to generate a DAB signal which could be useful and affordable for community and small commercial stations. For the trial the complex DAB multiplex signal was generated using computer software - rather than the expensive hardware used by the big boys.

The Ofcom report says: "As well as testing the viability and reliability of new wireless techniques for generating a Eureka 147 DAB compliant signal in a real world scenario and it also allowed various measurements, and comparisons with existing multiplexes to be made. The experiment successfully demonstrated that much of the infrastructure can now easily be implemented in software, and that integration with public IP networks improves accessibility while reducing the capital and operating costs quite dramatically."

The test also demonstrated that a low-cost, low power approach could deliver a reliable, high quality service using interleaved frequencies - which are left over between areas and unsuitable for use by larger networks.

Ofcom concluded:  "This work demonstrated that it is feasible to deliver DAB transmission infrastructure at much lower cost than currently required for equipment to deliver wide-area coverage. Nevertheless, significant further work is required to identify suitable spectrum for services making use of these technologies. In addition, it will be necessary to consider how they might be licensed to cover particular areas, especially in circumstances where there is a requirement to carry more than one service on the multiplex. When these issues have been resolved, these new techniques could find particular application for Community Radio or smaller scale commercial radio stations. These techniques might also assist in rolling out existing networks to serve more remote population areas where existing approaches might not prove to be cost-effective."

The full print version of the report can be found here:
http://stakeholders.ofcom.org.uk/binaries/research/radio-research/Software-DAB-Research.pdf