ACMA urged to deal with 'white space' use

The Australian Communications and Media Authority (ACMA) has been urged to build a framework to regulate how carriers could use 'white spaces' in each other's licensed spectrum in future.

University of Pittsburgh Professor Martin Weiss told the ACMA's RadComms conference in Sydney today that there was some urgency for regulators to find a way to manage dynamic spectrum allocation (DSA).

DSA is a subset of cognitive radio technology. It allows organisations to become "spectrum scavengers" by opportunistically identifying and using unused spectral 'holes' while avoiding interference, according to the International Journal of Digital Multimedia Broadcasting.

This could allow mobile telcos, for example, to take advantage of low spatial demand for a competitor's spectrum.

"DSA is going to be important going forward," Dr Weiss said.

"We have the luxury of time [to think about it] now but not in five years. It will run us over sooner or later so it's much easier to work [on now]."

Dr Weiss said that as incumbents collaborated, "questions of collusion need to be worked out".

The challenge for regulators in building a DSA framework was making sure it "articulated rights and responsibilities" clearly, so regulators would not need to micromanage such a scheme, he said.

"Having a framework that allows regulators to supervise it at arm's length rather than on a day-to-day basis is a key element," he said.

Dr Weiss also said regulators needed to limit "transaction costs" that otherwise might block new entrants from taking advantage of DSA to create new business models.

Transaction costs were defined as "all things that get in the way of completing a transaction", such as search or negotiation costs, or those costs associated with uncertainty.

"If there are a number of possible outcomes to hedge against, the costs may get so high that it's not worth [pursuing]," Dr Weiss said.

"I think that's where we're at right now with spectrum sharing arrangements, partly because the rights haven't been defined that well."

Dr Weiss said Australia was "fortunate" that existing spectrum management frameworks would allow the ACMA "to accomplish many of the goals" needed to enable DSA here.

The ACMA's communications infrastructure division general manager Maureen Cahill later told the conference that the regulator would look at the "windfall gains that are available ... if sharing is available" as part of a planned reform agenda.

Cahill said that the "nation-building infrastructure" agenda, combined with technology developments and consumer drivers, made now the "perfect time to think reform".

"We need to take this time to really consider the pace of change and what regulatory reform should be in the future," she said.

Telstra's spectrum policy group manager Brian Miller told the conference that smart radio technology such as cognitive radio and DSA was "one of the big technology opportunities to make [better] use of the [existing] spectrum resource".

He backed calls by Dr Weiss to ensure that DSA was implemented properly.

He also called on users to be made responsible for avoiding interference, saying that Telstra did not want to have to "police" DSA users accessing holes in Telstra's licensed spectrum.

"We don't want to go there, thanks," he said.