UHF Radio Licensing Australia

Click here to download this guide as a PDF

External Links

Click here to visit the ACMA compliance hub

Click here to visit the DGPS compliance page

Click here to download the ACMA DGPS fact sheet

If you'd like advice about becoming compliant with the new ACMA UHF radio laws, please contact your local Position Partners team on 1300 867 266. 


The Australian Communication and Media Authority (ACMA) has recently made changes to the 400MHz spectrum that will affect all transmitting GNSS base stations (DGPS).  A wide range of changes was introduced but most importantly for DGPS users, a change from 25 KHz channels to the adoption of 12.5 KHz channels. Segments were also set aside to be used exclusively for federal, state and territory government purposes.

Given the increasing use of GNSS equipment in Australia and the near continually transmitting nature of DGPS bases a number of single frequency channels in the 400MHz band have been reserved exclusively for area wide DGPS applications.

The operation of a DGPS base station needs to be authorised under Commonwealth law by a licence issued by the ACMA.

For detailed information see the ACMA’s DGPS fact sheet or other ACMA resources as listed in the 'external links' section at the top of the page. 

DGPS services can now be classified under two licence types:

  • Greater than 4 weeks
  • Fixed location
  • Protected against interference
DGPS is operating at a known, fixed location for greater than 4 weeks. These licences have the benefit of being coordinated with other radio communication services in the area of operation. These will also be different to the licences made available for Area Wide applications and offer protection against interference and the opportunity for higher transmit power.
  • Less than 4 weeks, short term
  • Large geographic area of operation
  • No protection from interference
DGPS are authorised to operate within a specified geographical area on an itinerant basis for short-term use. ACMA considers periods of up to four week short term where longer periods will require a sited licence. These licences carry no protection against interference and are not permitted to cause any interference.  Table 1 shows all the channels that are available for this purpose.

 DGPS transmit power

The ACMA has defined four geographic areas throughout Australia, known as high, medium, low and remote. These areas describe the level of radio communication use for the area and will define the transmit power for DGPS bases.

For Area Wide licences, high and medium density areas are restricted to 8.3 watts EIRP, whereas low and remote areas are licenced to transmit at 83 watts EIRP. For example, a 1W radio with a 6Db antenna is approximately 4 watts EIRP, a 20W radio with a 6Db antenna is approximately 80 watts EIRP. Users should always restrict the transmit power to the lowest usable setting for the application to reduce power consumption, heat and wear on the radio. Sited licences will carry special condition regarding the power output of the transmitter and are issued based on the site allocation.

Detailed information on these areas, including a Google Earth placemark (KMZ) can be found on the ACMA website under: Apparatus licence fee density area maps.



Segment channel

Frequency (MHz)

12.5 KHz bandwidth

25 KHz bandwidth

Segment S
















Segment X
















Table 1 – Area-­wide single frequency channels reserved for DGPS

Channels 362-366 in segments S & X may be assigned for AREA WIDE DGPS applications. Four 25 Hz channels are also available and will work with Topcon equipment but the 12.5 KHz channel bandwidth is preferred.

Due to the limited number of channels assigned to AREA WIDE use, interference with DGPS systems in the same vicinity is possible. The ACMA recommends that DGPS operator licence at least two channels to allow for a backup in the case of interference.

Repeaters may be operated under a SITED licence however the supplementary device must be recorded on the licence. Repeaters are generally not permitted on AREA WIDE licences.


Position Partners is committed to helping businesses manage this change, regardless of the brand of GNSS equipment they have. We have extensive experience in managing sites with multiple brands of survey and machine control and understand that radios pose the single biggest challenge in successful site-wide GNSS integration.

Topcon has invested heavily in ensuring very little disruption for its Australian customers when making this change. All Topcon digital radios can be firmware upgraded to be fully compatible with the changes and also be fully compatible with both Leica and late model Trimble equipment. Position Partners will work with your company and help with a rollout plan to minimise any downtime. Some charges may apply on firmware upgrades to older Topcon equipment.

In order to combine multiple brands of GNSS or to optimise your Topcon site, some basic understanding of radio terms is an advantage. The following is a short summary of the main settings for modern DGPS radios:


Modulation is how the data is put onto the carrier frequency. The fundamental characteristics of radio waves are frequency, amplitude and phase. In typical RTK radio solutions we utilise the following modulations: GMSK (Gaussian Minimum shift keying) and 4-FSK (Frequency shift keying).


Protocol is how the message is formatted on the carrier.In a typical RTK radio solution we utilise the following protocols: PDL, SATEL and Trimtalk.

Link Rate

The link rate is represented by a Baud rate and is the rate of data transfer between the transmitting radio and the receiving radio. The link rate directly affects the bandwidth of the solution within the selected modulation.


This is how much of the radio spectrum is occupied by the modulation.  Typical bandwidths under the radio licencing are 25Khz and 12.5Khz.

Message Type

This is the language used for correctional data transfer between the GPS base unit and the GPS rover. Typical message formats for RTK solutions are CMR (compact measurement record) and RTCM-3 (radio technical commission maritime).

Duty Cycle

Duty cycle is a specification on DGPS radio hardware, which details the radios capacity to transmit data at a rated output power for the transmission time. This figure is displayed as a percentage and will indicate how much data can be transmitted by the radio.




25 KHz

12.5 KHz


Link rate

Message type

Duty cycle

GMSK (PDL, Trimtalk)





4LFSK (PDL, Satel)






Aligning your UHF DGPS settings is crucial for site-wide compatibility. Poor duty cycles can impact your DGPS latency and potentially affect your rover accuracy. All these aspects can be mitigated by speaking with Position Partners for your UHF GNSS site design.

Obtaining a licence

The operation of a DGPS base station needs to be authorised under Commonwealth law by a licence issued by the ACMA. The ACMA has an online Register of Radio communications Licences on its website that can be used to identify the types and technical parameters (e.g. frequency) of services that operate at radio communication sites.

Position Partners, as a professional supplier of transmitting DGPS equipment, cannot program equipment with frequencies that do not have a valid licence or a third party use agreement with the owner of the licence. This is in accordance with the Radio Communications Act.

Position Partners can assist with a range of services to ensure your company is not only compliant with ACMA, but also has optimised its use of the spectrum and maximised compatibility of DGPS equipment. These services include:

  • Applying for UHF Sited and Area wide licences
  • Consulting on sited base station setup
  • GNSS brand compatibility
  • Coverage prediction
  • Third party authorisations
  • Site radio surveys

Hire equipment & Third party authorisation

Under the Radio Communications Act there is a provision for third party authorisation for cases such as short-term hire. A third party authorisation is a private commercial agreement that allows a spectrum or apparatus licensee to authorise another person or organisation to operate a radio communications device.

Position Partners has in place a third party authorisation procedure that can cater for short-term hire, for use when a company doesn’t have a licence or where or their current licences are receiving or causing interference.

Uploading your new frequency channel table

The Position Partners support team is always ready to help with any enquires at 1300 867 266. All Topcon GNSS equipment can use a FREE utility program called TRU (Topcon receiver utility). This program is available for both windows mobile and windows PC computers. TRU has a range of functions include static logging, firmware upgrades and UHF radio settings. Uploading your new channel list is as simple as connecting the GPS with TRU and uploading the new ‘DCF’ file created for you by your local Position Partners branch.

For a more comprehensive look at your company's responsibilities and the impact of this change, please contact one of our local spectrum managers by calling 1300 867 266


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