Interim arrangements for W-band fixed satellite service earth station transmitters

We received 4 submissions to this consultation. Two submissions were in support of the proposed decision. Two objected, raising concerns about:

• Potential for interference to a cloud and fog radar system near Melbourne Airport operating under an Australia-wide licence (location not visible in the ACMA licensing database).
• Interference risks to adjacent-band Earth exploration–satellite (passive) services.
• Reflected satellite signals potentially causing interference to radio astronomy receivers.
• Potential interference to unlicensed radio astronomy receivers under test at CSIRO’s Marsfield site.
• Potential impact on future space-based radio astronomy observations.
• Use of subsection 10(10) for services not listed in the Table of Allocations, which could prejudice future decisions on W-band FSS usage.

Upon review of these submissions, the proponent withdrew the Melbourne site and will engage directly with the radar operator to decide compatibility. The site is no longer under consideration by the ACMA.

Assessment and decision

After analysis against our Unspecified services policy, and considering licence assessment criteria and conditions to be applied under subsection 10(10), we are satisfied that W-band earth station transmitters in Perth and Sydney, communicating with non-geostationary space stations in the fixed-satellite service, are unlikely to cause harmful interference to other services. Decisions under subsection 10(10) in the ARSP have been made for the proposed Perth and Sydney sites.

Mitigation measures

To further reduce the potential impacts on existing and future services:

• Licence applications will be assessed under our Procedure for earth and earth receive licensing and registering earth stations.
• Earth stations will be authorised on the condition that no interference is caused to any licensed radiocommunications station or service, and no protection from interference by such stations or services will be afforded.
• Licences will be issued for a non-renewable term of one year, reflecting ongoing W-band developments internationally and allowing future decisions to incorporate global progress.
• Future requests will be considered on a case-by-case basis.

Response to objections

We have written to the objecting parties outlining the reasons for our decision, including:

• Adjacent-band EESS passive sensors:

  While current work within ECC is ongoing and subject to further analysis, the draft report under preparation includes a simulation scenario with 100 gateway sites, each hosting 32 earth stations (a total of 3,200 earth stations) across 2 million km².  The results suggest that it could be technically feasible for W-band FSS gateways to operate without impacting EESS (passive) services.

  For Australia, the proposed decision considers only three sites – Melbourne, Perth, and Sydney (reduced to 2 following the withdrawal of the Melbourne site). Given this small number compared to the ECC study, it is considered highly unlikely that W-band FSS earth station transmitters authorised under the decision would cause harmful interference to passive sensors on Earth exploration satellites.

  Licences will be limited to a one-year, non-renewable term, allowing for review and adjustment if required.

• Future space-based radio astronomy missions: 

  Licences will be issued for one year only, enabling reassessment as international developments occur.

• Use of subsection 10(10): 

  This provision was introduced in the 2017 ARSP following public consultation to provide flexibility for spectrum uses not anticipated at the time. Decisions are assessed under the Unspecified services policy, and we consider subsection 10(10) an appropriate spectrum management tool to enable innovative spectrum uses for the public benefit. W-band licensing to support consumer LEOSat service offerings is an example of these benefits.

Next steps

We have issued the first W-band earth station licences.

We thank all parties for their submissions and engagement in the consultation process.

This consultation has closed. You can view the submissions we received below.

earth station

Radiofrequency Spectrum

radiocommunications

We are proposing interim arrangements to support earth station transmitters in parts of Melbourne, Perth, and Sydney in the following frequency ranges: 

• 92–94 GHz
• 94.1–95 GHz
• 95–100 GHz
• 102–109.5 GHz
• 111.8–114.25 GHz.

W-Band arrangements for earth stations are under consideration in the USA and Europe to support new satellite services. This includes gateway earth stations supporting broadband satellite services. The Australian Radiofrequency Spectrum Plan 2021 (ARSP) does not currently allocate the W-band for fixed-satellite services (FSS).  

Given this lack of an allocation and the generally light use of the band in the proposed locations, we do not intend to undertake a full review of W-band. However, we want to develop interim arrangements while we monitor developments. The lack of an FSS allocation in the ARSP also means that we will need to invoke the provisions of subsection 10(10) of the ARSP if we decide to implement the proposed arrangements.

Subsection 10(10) allows a frequency band to be used for an unspecified service. This is on the condition that prior to its use, we are satisfied the service is unlikely to cause harmful interference to other services. Approval must be provided in writing and published on the ACMA website. 

Our preliminary view is that harmful interference is unlikely to be caused to other services, provided earth stations are located within a 2 km radius centred at the following coordinates (GDA94 datum):

• Sydney: -33.785073°, 151.131214°
• Melbourne: -37.823009°, 144.915390°
• Perth: -31.864147°, 115.895866°

To further mitigate potential impacts on existing and future services, we propose the following measures:

• Licence applications will be assessed in accordance with our Procedure for earth and earth receive licensing, and registering earth stations.
• Earth stations will be authorised on the condition that no interference is caused to any radiocommunications station or service, and no protection from interference by such stations or services will be afforded.
• Given that W-band arrangements are under consideration in the USA and Europe, licences will be issued for a non-renewable term of one year. This will allow international developments to inform decisions.
• We will consider any future requests on a case-by-case basis.
• These are interim arrangements, with any access conditional on a future review of the band. Approval cannot be taken as a precedent for future requests.