The Australian Communications and Media Authority is considering re-farming spectrum that underpins Telstra microwave links and radiotelecommunications services in rural Australia.
The communications regulator has commenced a review (pdf) of the 1.5 GHz band in Australia with a view to re-allocating it for use by mobile broadband services, depending on industry feedback.
Telstra could be the biggest loser in any major re-assignment. As of January this year, Telstra held 83.5 percent of licenses in the 1.5 GHz band, according to the regulator.
The next biggest holder of frequency licenses in the band is Aussie Broadband with 2.5 percent.
The 1.5 GHz band is traditionally used by Telstra for fixed point-to-point links and to deploy microwave systems for telephony services to meet its universal service obligations (USO) in remote and low-density areas.
A Telstra spokeswoman welcomed the review but sought clarity on how its existing investments would be protected.
"Adequate alternative arrangements for Telstra's existing fixed link systems in this band (used to deliver Universal Service Obligation public telecommunications services in regional and remote areas) would need to be developed and agreed before any such reallocation of spectrum could take place," a spokeswoman told iTnews.
The other uses assigned to a portion of the 1.5 GHz band is digital sound broadcasting (although apart from a couple of trials back in 1997, no one uses it) and for aeronautical systems used by the Department of Defence.
Only a year ago, Telstra sought for the digital broadcasting allocation to be reclaimed for use by point-to-point microwave services.
The ACMA has also specifically asked Defence whether their needs for the 1.5 GHz band are increasing or decreasing.
The ACMA is fast-tracking a review of the 1.5 GHz band as it sees international regulators starting to harmonise the 1452-1492 MHz block for mobile broadband services.
Its review goes a step further than international regulators, though, in examining the entire block of spectrum considered to be 1.5 GHz - consisting of 1427.9-1462.9 MHz and 1475.9-1510.9 MHz band segments.
An earlier ACMA initiative, dubbed Towards 2020, highlighted the requirement for up to 300 MHz of spectrum to meet demand for mobile broadband services by 2020.
About half of that new spectrum is expected to be required by 2015. That needs will be partially filled by the digital dividend auction of 700 MHz and 2.6 GHz spectrum at the end of the year.
A formal response by the ACMA on Towards 2020 is expected some time later this year.