You may recall that I reported an event of jamming of police radio in Sydney back on 12 December 2005, during the Cronulla and Brighton-le-Sands race rioting. No mainstream news organisation made any mention of the jamming at the time.
The Sydney Morning Herald reported on 17 February that police are advising that the affected channel has been converted to digital to prevent recurrences of jamming:
Police radio more secure
February 17, 2006
THE NSW police radio channel that was interfered with on the second night of revenge attacks after the Cronulla riots has been converted to a more secure digital channel, police say.
The incident occurred on December 12 between 10.30pm and 11.30pm. On that night, groups of young men caused malicious damage to cars and shops and assaulted a number of people in the Sutherland Shire area. Assistant Commissioner Bob Waites, who is the spokesman on communications, said interference of the police radio network was "not an infrequent occurrence".
"It’s not as serious as it sounds," he said. "The radio operator could still hear the other police even though this person was playing music over the channel. We immediately switched to another channel."
All well and good; reliable 2-way radio communications for police are of paramount importance to public safety. Digital radio is less susceptible to interference and eavesdropping. However, I dispute Waites’ estimation that police radio operators were able to hear the units in the field during the jamming.
Most police radio systems employ ‘repeater’ stations which listen for signals on one channel then retransmit them on another. On the night of 12 December, some person unknown to me had set up a gateway website (then located at http://speedy.akadns.info/streams/8000/sydneypolice.wax but now offline), which carried the audio from a scanner radio, which I and many other people used to listen to the police broadcasts on the night.
From what I could gather while listening, the radio operator at the police base station couldn’t hear the field units and frequently asked them to repeat their transmissions. The jammer appeared to be transmitting on the input channel to the repeater, which blanked out all the field units trying to access it.
The police radio control operator several times told the field units to change channel. The person operating the radio-to-web gateway didn’t have much trouble changing frequency to follow. Neither did the jammer, who carried on interfering until about 1am Sydney time on 13 December 2005, well past the 11.30pm time as stated by Assistant Commissioner Waites.
However, unless the digital radio system is encrypted, there are still scanning radios available which can receive those digital signals- you can buy them at Dick Smith.
Let’s hope the police have got the radio system sorted. I sure wouldn’t want to be the person who needed help while the police 2-way system was being jammed.
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