[TheList] Squawking Tones on Police Channel & High Frequency Tone on Channel

Sun Mar 20 12:01:09 AEDT 2022

Hard to say...  but most likely that will be the case, yes you'll no 
longer hear police.

The Government is bringing in NGCC (Next Gen Critical Communications) 
network which will be P25, Cellular and IP based telecommunications 
setup, similar to Australia, America, etc.  The ESA/UHF analog networks 
will be shut off.
It will have Police, FENZ, St John, WFA, and possibly CivDef etc. It's 
possible that some or all of it will be encrypted, that will be up to 
each orgainization.  I'd imagine that it will follow along with the 
current Auckland, Wellington, Wairarapa and Canterbury setups where 
Police are encrypted.  But that could change as happened in Victoria on 
the MMR/RMR networks (basically speaking MMR is UHF, RMR is VHF)  where 
Ambulance were unencryped, but that's changed and is now encrypted..  
Encryption is done on the subscriber unit - P25 supports encryption.

The current P25 network I understand to be owned by the Police, this new 
network will not be.  I would assume that the Police will sell their 
equipment so they no longer have to worry about the repeater networks 
falling over, that would become the NGCCs problem, but they would keep 
their current radio techs as they still need people on the ground 
looking after vehicles/handhelds... I will also assume that NGCC won't 
have any interest in dealing with subscriber units as it's a lot to 
manage - they'll have enough on their plates to deal with, running a 
national trunking repeater network. I also assume that Police will want 
to keep their codeplugs close to their chest.  FENZ/Police have their 
own radio techs, so it'd be business as usual for them, except no more 
repeater work - they're multi talented in that they do radio, telephony 
and IT stuff.  St John use Vital for repeaters, but contract Tait to 
subcontract radios, each Civil Defence area seems to do their own thing 
for radio work.  I don't know much about WFA other than they use a 
couple of talkgroups on the Wellington P25 network.  Others that could 
join would be government departments... Aviation Security, MBIE 
(Immigration etc)   I will assume that Corrections will remain as they 
are with their current LTR setups that are moving over to DMR as they 
really need prison specific coverage, and keep the prisoner transport 
vehicles on Vital.

On 20/03/2022 1:24 pm, Tim Devaney wrote:
> Are we not going to be able to receive the police soon ??
>
> On Sun, Mar 20, 2022, 12:09 DogSec - Richard 
> <richard at dogsecurity.co.nz> wrote:
>
>     Hi BJ,
>
>     Years ago someone did a write-up about it on here, but basically
>     it's a form of SCADA for monitoring sites remotely.  Some sites
>     are often not easy to get to and may have access issues such as
>     being helicopter access only. These sites have quite large battery
>     banks, as mains power may be flaky.  The SCADA allows for inputs
>     and outputs to be monitored remotely.  They are often polled at
>     specific times, which is why sometimes you may hear the tones
>     underneath voice comms.  If the controller polls and doesn't get a
>     response back then it will retry X amount of times (if programmed)
>     then assumes the site is dead, and alerts get generated.  A
>     variety of things can be monitored. Often these are only 'analog'
>     inputs so you only get very specific details..  You could see
>     things like
>
>     Battery Bank A is 100/75/50/25% (maybe not even in that much detail)
>
>     Generator On/Off
>
>     Entry Door OPEN/CLOSED
>
>     Alarm ACTIVATED/DEACTIVATED/IN ALARM
>
>     SOLAR ON/OFF (IE is there voltage coming into the system on the
>     Solar lines)
>
>     REPEATER POWER ON/OFF  (some repeaters can have an output that's
>     activated when it's in a certain state)  As Daryl mentioned, it
>     would be a (probably unreliable) way of determining if a repeater
>     is working or not.
>
>     With the NGCC being implemented, a lot of this will eventually
>     become redundant as most things like SCADA would be converted to
>     IP based, and digital radio is also IP based, meaning a lot of
>     this could be sent over a text message over the radio network.  I
>     assume P25, but DMR will prioritize voice over messaging.
>
>     As for the screeching, lots of factors could be causing that. 
>     I-band links shouldn't really be used for monitoring as they're
>     only point-to-point or point-to-multipoint links meaning you
>     really need to be in line of the path for it to be received. I'd
>     recommend use the VHF/UHF frequencies.  Once again, with things
>     turning to digital soon, they'll probably be redundant with the
>     links will be done over IP.
>
>     Cheers,
>
>     Richard
>
>     On 20/03/2022 11:23 am, Darryl Healy wrote:
>>     Those tones are something to do with the linking with all the VTGs.
>>
>>     They happen every 4 hours at midnight and so on.
>>
>>     Someone will no doubt give a more technical explanation of them soon.
>>
>>     On Sun, 20 Mar 2022, 11:01 BJ, <bjcuizon151 at gmail.com> wrote:
>>
>>         Hi all,
>>
>>         Was in Dunedin recently and tuned in to police comms. Anyone
>>         know what those squawking tones on some police channels are?
>>         It doesn't sound like fire selcall but more like a really
>>         short (~1 sec) burst of what sort of sounds like a part of
>>         the old dial-up handshake.
>>
>>         Also, was listening to firecom and ambo thru the I-band link
>>         in Chch and on some link channels there is a really high
>>         pitched tone that is present when someone keys up. It can
>>         only be heard on a radio with no audio filtering/DSP as my
>>         Tait seems to cancel it out. Does anyone have an idea what
>>         this is as well?
>>
>>         Thanks in advance,
>>         BJ
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>>
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