Making the switch to Digital TV

29 Sep 2009

As Australia heads towards the first switch-over to digital-only television services in 2010, Broadcast Australia is working with the Federal Government to provide advice which will influence the Green Paper that will outline how the use of television spectrum—in particular the UHF band—is to be rationalised. This will streamline the digital transition from a consumer point of view, minimising disruption to viewing in the long term.

The upper portion of the UHF band (>700 MHz) is attracting interest from government regulators all around the world as a candidate for next-generation services-such as wireless mobile broadband, enhanced digital TV services (eg 3D or super high vision), mobile TV and some non?commercial applications. In addition, digital radio services-such as DAB+ being deployed in Australia-could be assigned to liberated VHF Band III spectrum.

Recent spectrum planning studies by Broadcast Australia demonstrate that 126 MHz of UHF spectrum (694-820 MHz) could be made available for reassignment to next-generation services, given appropriate 'restacking' of spectrum. This means any existing digital broadcast services above 694 MHz would be relocated to different channels in the VHF or lower UHF band, taking advantage of the spectrum made available by the discontinuation of analogue television services. 

According to Stephen Farrugia, Broadcast Australia's Technology Director, the company's studies made allowance for the two so-called 'unassigned channels' earmarked for new services such as datacasting and mobile TV, plus considered a hybrid terrestrial/satellite model for enhancing digital coverage in regional and remote areas. Here, new terrestrial 'gap filler' transmission sites would be deployed, and existing 'self-help' facilities upgraded to digital, where practical. Digital satellite services would be provided as a safety net.

"A 'digital dividend' of 126 MHz is definitely achievable using the hybrid model to combat digital television coverage deficiencies," Farrugia said. "We believe that it's important to provide as much terrestrial coverage as possible, since this is the only way to deliver localised content-in particular local news programming and local advertising. It's also a much cheaper consumer proposition than satellite, and is more resilient to environmental factors such as heavily treed areas or rain fade."

Broadcast Australia estimates that work of varying levels of complexity would be required on around 200 sites across the country, with frequency changes to around half the existing Digital TV services, to achieve the proposed digital dividend. Digital switchover is scheduled to be completed by end-2013, with Digital Dividend spectrum expected to be released between 2011 and 2014.

Farrugia believes there is merit in timing the restacking of frequencies to coincide with the switchover to digital-only services. "Many viewers will need to do little more than retune their digital television receivers," he said. "However, some viewers may need to purchase new rooftop antennas and/or set top boxes or television sets. It makes sense for them to go through the process only once! The sooner they know what the ultimate channel frequency and terrestrial coverage in their area will be, the sooner they can ensure they have the right equipment."

"The important thing to note is that the digital dividend will benefit society as a whole, through the enabling of new services," Farrugia said. "The market will drive demand, and by making the spectrum available we allow innovative services the chance to get off the ground and promote competition, choice and lower prices."

Have you got a question about the Digital Switchover or Digital Dividend?  Ask Broadcast Australia at newsletter@broadcastaustralia.com.au