Play ball on Brisbane Digital Radio: Rebel FM’s Aaron Jowitt

The discussion about DAB+ overspill from Brisbane continues, with this contribution from Aaron Jowitt, proprietor of Rebel FM.



The recent article by Brad Smart and subsequent follow up article by Joan Warner highlights the confusion regarding digital radio planning, not only with some broadcasters but with decision makers and those with influence on the radio industry.

It is commonly known to CRA and the ACMA that there are not just two, but five regional adjacent markets potentially impacted by a Brisbane DAB Mt Coot-tha proposed move to 50kw omni directional;

  • Gold Coast – overspill concerns
  • Sunshine Coast – overspill concerns
  • Ipswich – overspill concerns
  • Rebel Gold Coast hinterland & Logan – overspill concerns
  • Rebel Wide Bay – co-channel interference from Brisbane DAB in our Wide Bay market increasing from 30% level (based on preliminary indicative ACMA channel allocations and modelling)

The Rebel Logan market includes an area that state government planning forecasts project will easily become the largest solus population centre within our market.  Coverage modelling indicates the majority of it will receive indoor suburban grade fortuitous coverage from Brisbane DAB @ 50kW OD with negligible interference.
Joan Warner mentioned Brisbane DAB licensees and CRA are aware of overspill concerns and are in ‘constant dialogue’ with broadcasters to find a way forward and help ensure all broadcasters have high quality coverage within licence areas.  Apart from 4TAB, our company has not had any dialogue with Brisbane DAB licencees or CRA on this.

If Brisbane were to reduce Mt Coot-tha power and establish a few DAB on channel repeater sites (running at full licenced power), they could likely serve their market better than they do now with less overspill than 50kw OD, and reduce the co-channel reuse distance to help free up spectrum in regional markets.  It’s a promising solution, and needs to be openly discussed.

We have larger concerns with;

  • Gold Coast DAB draft planning – proposed co-siting with our markets existing FM services on Tamborine, and creating extensive overspill across Tamborine Mountain. We commend the ACMA for postponing consideration of that proposal.
  • Rebel Gold Coast hinterland/Logan DAB preliminary indicative planning – requiring a cost prohibitive five DAB site outcome attempting to serve ~45,000 people in an area of just 30km x 40km, but suffering extraordinary predicted interference levels of >30% impacting 10,000+ people in the Jimboomba and Tamborine population centres. Unworkable.

The shortage of regional DAB channels for the commercial sector is a huge underlying problem. For example, the indicative proposed co channelling of Rebel on Tamborine Mountain with 2MW on southern Gold Coast is a recipe for massive levels of mutual interference, with the transmitter sites separated by only 30km line of sight.  This effectively may write off DAB for both broadcasters in that region, unless one agrees not to broadcast, leaving the other market unserved.  It’s a real mess. 

The only known solutions are indeed quite challenging, but they do exist; 

  • Licence Area Aggregation – as suggested by the ACMA, ABC, Rebel, CBAA and others to markedly improve channel availability, but rejected outright by CRA.  Or;
  • DRM+

The ACMA has a near impossible planning task sandwiched between the Government’s DAB directives and CRA being the only sector body rejecting market amalgamation out of hand.  We hope the government or the ACMA shortly compel CRA to play ball for the long term benefit of all, but unfortunately there seems little appetite for that so far.

This crucial ACMA DAB spectrum planning stage will progressively move to lock in long term regional outcomes. This is the worst time for CRA to be avoiding the big issues and not engaging on real solutions, no matter how unpalatable they may first appear.   On the current path, there is no doubt select unlucky markets will end up with badly compromised DAB outcomes with high interference levels, an otherwise avoidably large number of costly infill repeaters, or coverage that long term falls well short of the parent FM services. 

Now is the time for all broadcasters and CRA to work pro actively with ACMA and government to change the current flawed direction for a better outcome for broadcasters and listeners who deserve better.

Aaron Jowitt

Director,  Rebel Media

Rebel FM is an Active rock-formatted radio station, based in the Gold Coast and broadcasting across regional and remote areas of Queensland and New South Wales. First broadcast as SUN FM in 1996, it is owned and operated by Rebel Media.

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