The NSW Government has commenced Australia’s first trial of mobile phone jamming at one of the state’s prisons, in an effort to clamp down on illegal mobile phone use by inmates.

The trial will be conducted at Lithgow prison for nine months and could potentially be rolled out to all the state’s prisons if successful.
Corrective Services will deploy CJAM jammers due to their ability to stop signals in a precise perimeter.
The jammers and accompanying distributed antenna system will be provided by chosen suppliers WiComm and Lan Installations for contracts worth $462,000 and $178,000 respectively.
Using jammers to block mobile signals is illegal under Australia law, but Corrective Services has been granted an exemption to the Radiocommunications (Prohibition of PMTS Jamming Devices) Declaration 2011 by the Australian Communications and Media Authority for the trial, which is valid until June 30 next year.
The trial was initially slated to run for a year but has been revised down to nine months. Corrective Services declined to detail why.
The proposal to crack down on illegal mobile phone use by prisoners by jamming mobile signals first arose in 2009. Two years later Corrective Services conducted lab tests which quashed concerns that blocking signals inside prisons may affect signals in surrounding areas.
Once the trial is complete Corrective Services will report to ACMA on its success, which will be determined by how it managed interference, consumer complaints and information, as well as the effectiveness of the monitoring and reporting arrangements in place for the trial.
Jamming not the be-all for Australia’s prisons
However, using jammers to block signals in Australia’s prisons is not expected to be the all encompassing solution.
Containing a signal block to a particular area is difficult to achieve without having leakages affecting surrounding residents, David Stone at New Zealand’s Telecommunications Carriers Forum told iTnews.
The New Zealand Government has hit several roadbumps since introducing jamming technology in all of its 20 prisons in 2009, with reports of cost blowouts, radiation leakage and sparse jamming coverage.
The jamming technology used in NZ prisons reportedly only covered an average 60 percent of each facility, with the government forced to fork out more cash than expected to upgrade and fix the system. It also received complaints from residential areas around the prison.
“There were certainly instances where neighbouring premises were significantly negatively impacted. The actual signal strength was amped up in those sectors to cover it, but some people had negative experiences,” Stone said.
The NZ Government has declined to detail what mix of technology it has used in its jamming project. It is understood the government initially used jammers but on the advice of the local telco industry has started building cell sites within prison facilities.
Paul Brislen of the Telecommunications Users Association of New Zealand told iTnews that had the NZ Government listened to the technical advice it had been given, neighbours would not have been affected.
“The telcos said the easiest thing to do would be to put a cellphone tower in the prison, so any smuggled cell phones would lock onto it, but they didn’t want to do that, despite the telcos saying it was the cheapest and best way of doing it. In the end they were forced to implement some kind of jamming regime,” Brislen said.
He said blocking signals was almost impossible to achieve.
“Cell phone signals from the tower to the phone are designed, much like the internet, to lock onto and get around any kind of damage, and all of this kind of stuff is treated as damage, so the signal works really hard to get around it. [The devices are] working quite hard to connect to the nearest tower,” Brislen said.
“It’s important that whatever is trying to jam the signal can shrink and breathe with the cell sites.”
iTnews understands the NSW Corrective Services department received similar advice from the likes of Telstra, Optus and Vodafone, and will eventually trial other technologies alongside jammers. Lithgow Jail is understood to be fit for a jamming-only trial due to its remoteness.
Australia’s telcos, through industry body AMTA, are understood not to be in favour of a regulatory response mandating one type of technology.
AMTA declined to comment on the jamming trial technology but said it had clearly enunciated the principle that any trial must isolate jamming to the test area.
Corrective Services did not respond to request for comment.