The ACMA and Defence to share HF facilities

The ACMA and the Department of Defence will collaborate on an HF system.

A fortuitous confluence of needs will see the Department of Defence and the ACMA collaborate on an HF system that will fulfil the needs of both agencies.

The ACMA, the Department of Defence and the Defence Materiel Organisation (DMO) have finalised an agreement that will let the ACMA use four HF receiver sites in mainland Australia that are part of the Defence High Frequency Communications System (DHFCS).

This access will enable the ACMA to put in place a new high frequency direction finding (HFDF) and monitoring system, while closing three of its current HF receiver sites.

For decades, the ACMA and its predecessor agencies have operated a high frequency radio DF system for the purpose of locating and identifying sources of interference. Receiver stations spread across the nation are used to triangulate in on such sources, whether domestic or overseas, whereupon the regulator takes steps to resolve the issue.

The ACMA was allocated $10.5m for a new HFDF system in the 2013-14 budget, but by sharing facilities with Defence it will be able to reduce that expenditure by around $2m.

Defence is upgrading its DHFCS as part of Project Nullarbor, which will be completed by Boeing Defence Australia in late 2016.

“I welcome this historic agreement between the Department of Defence, the Defence Materiel Organisation and the ACMA,” said  ACMA Chairman Chris Chapman.

“At a time when we are all operating under significant financial constraints, it is an example of how the public service can innovate and do things smarter, and work across traditional boundaries to improve outcomes and reduce costs,” he said.

A need for change

Faced with ageing technology and several sites that had become less than ideal, several years ago the ACMA decided it needed to undertake an upgrade process that would involve replacing equipment and possibly selecting new sites.

“We’d been conscious that we needed to do something with our HFDF for some time,” said Mark Loney, the ACMA’s executive manager of spectrum operations and services, who was assigned responsibility for the service in 2010. “There’d been some preliminary work done before then, but we were really getting to the point where we needed to do something. HF is a band that’s actually thriving despite the fact that in some ways it’s very old technology; it’s still heavily in use in all sorts of things from broadcasting to military, aviation and so on.”

The ACMA’s extant system was 20 years old and technicians were having to scour the internet looking for spare parts. There were also issues with the sites.

“We’ve got one site in Birkdale in Brisbane, which is now essentially surrounded by city. Now from a strictly technical point of view, it was still acceptable for us to use as a receive site for HF, but we’d had vandalism and some other problems,” said Loney. “We also weren’t convinced that technically it would be a good site for the next 20 years, so we wanted to move from there.”

The ACMA also has a receiver station on the Cox Peninsula near Darwin, a location which has been, and still is, used by other government agencies for radio equipment. In the 1990s it became subject to a native title claim, which is still unresolved. It’s also a very difficult site to access and service, being a half-day drive from Darwin. So the ACMA decided to move. “We were originally going to move onto Defence land at the Shoal Bay receiving station. Airservices have a facility there and we were going to sublet from them,” said Loney.

The third site, in Western Australia, is at Bullsbrook near RAAF Pearce. “We’re actually on Defence land there. We were going to stay there, that was fine, although the curve ball that turned up with that in the last year was that the WA government is about to put a whacking great highway through it,” said Loney.

“The Quoin Ridge site in Tasmania is good. It’s actually between Hobart and Hobart Airport; and despite the fact there’s an airport just down the hill, it’s actually in a very good receiving spot,” said Loney. “It meets certain ITU criteria for voice monitoring as well as DF. It’s one of the few, if not the only, HF receive sites in the Southern Hemisphere that has that rating or that meets that criteria. So we always wanted to keep Quoin Ridge.”

The ACMA's HFDF site at Quoin Ridge in Tasmania was upgraded at the end of 2014.

The ideal solution

“We came to the view that we needed to continue to have the DF capability and so we went and looked at ways in which we could provide or access that capability,” said Loney. “The obvious one was to keep doing what we were doing, which is to have our own system. Another was to look and see if there was somebody else in Australia who could do it. And Defence were the obvious people to talk to, so we went and talked to them. What they said to us at that time, 2010-11, was no, they didn’t have an HFDF capability and they had no plans to acquire one.”

So the ACMA worked up a proposal to government, calling for funding to replace its DF system with a new one. “We were ultimately successful in getting that,” said Loney. “We went to government and said, ‘We need to have the capability, we’ve looked at alternatives and there don’t appear to be any.’ So we asked for money to do it ourselves - we got $10.5m.”

That was in May 2013. The ACMA went out to market very shortly afterwards, calling for tenders for a new four-site system with receiving equipment. It was during the tender process that the agency had reason to consult with the DMO, only to realise that the DMO was in the middle of the Project Nullarbor upgrade of the DHFCS.

“When our technical guys talked with the DMO technical guys, it became obvious that they were essentially building an HF receive capability that could also be used for direction finding,” said Loney.

The DHFCS has four stations - Townsville, Wagga Wagga, Darwin and Exmouth - each with separate transmit and receive sites.

Access to this network would mean the ACMA could shut down Birkdale, Cox Peninsula and Bullsbrook and not have to worry about getting new mainland sites, while retaining the Quoin Ridge site, which underwent an upgrade in late 2014. “We’d have access to four receiver sites on mainland Australia, which would actually in some cases give us better result,” said Loney.

The ACMA began discussions with Defence about how all this could work and a little over a year later there was an MOU in place.

Defence is making some changes to the DHFCS to accommodate the ACMA’s requirements. This will be complete in about two years, which is when the agency will shut down its mainland sites.

Quoin Ridge has just been upgraded with equipment from UK company Roke. “The Roke system that we put in is a really nice piece of work. One of the things it does is give you a great circle line of bearing back to where the interfering signal is coming from,” said Loney. The advantage of the new system is that it provides the “ability to receive a signal, process it and display it in a way that assists the user”.

Receiver equipment at Quoin Ridge.

What about Defence security considerations? “We’re partitioned from them. We have no visibility to what Defence is doing,” said Loney. “We can drive the receivers across the frequency range we need, which is 2-30 MHz. We can run two tasks simultaneously, and Defence has a capability to run a much larger number of tasks. We’ve essentially bought some capacity on their system, and they’ve put a ‘wall’ between us and what they’re doing.”

Complaints department

The ACMA responds to complaints from users who experience interference on their frequencies. An example is the ongoing challenge for the aviation industry posed by fishermen in Asia who buy land mobile radios, which may be front panel configurable and may have the whole band available to them, and who then go looking for quiet channels. They tend to find the aviation HF channels, which are clear most of the time. “Airservices Australia is a big customer of ours,” said Loney.

The ACMA also works with its counterparts offshore; in particular, Industry Canada, Ofcom in the UK and the FCC/NTIA in the USA. “And we work with other administrations in our region, although that’s less common because we’re the only administration that has a real HF capability,” said Loney.

“We operate on a regulator to regulator basis, so if we see a signal coming out of a particular country, we’ll contact our regulatory counterpart over there,” adds Loney. “Typically it’ll be resolved. Regulators cooperate on these sorts of things. Most people in the HF band are well behaved because of the propagation characteristics and because HF is often used for last-resort communications.”