WA Police Changeover to Digital Radio

Rockjet · Post by **Rockjet** » Thu Aug 02, 2007 8:45 am

I think it will be a while before regionals get them, Geraldton is still in carrier pigeon!!!

Markmywords · Post by **Markmywords** » Thu Aug 02, 2007 10:11 am

I heard a freo car get a job on tardis a few nights ago, just wondering if any of the wapol guys might know if they have had a problem with batteries running flat or does the tardis turn its self off when the vehicles off.

I know in melobourne they had a problem guys leaving the screens in the car on and ending up with flat batteries.

CHEV4EVR · Post by **CHEV4EVR** » Thu Aug 02, 2007 10:23 am

yorky wrote:
GC101 wrote:
auntys_eyes wrote:The officers confirmed that both West Metro & Central Metro regions have gone fully digital
and northwest and mig and teg and rog and rail unit and the list goes on hahah suckers
Then why can I still hear them fine on CH34 + CH21/41? Digital yes, but you can still hear them on analog.

Until everyone is on board transmissions will still be patched through on the analogue network. Otherwise how would a South Metro or South East Metro vehicle be able to go into Central or West Metro and use the radio.........
You can tell by listening to a vehicle transmissions as to whether they are using analogue or digital, it is quite distinctive.
In relation to battery problems there have been none as they have power saving functions to prevent running the battery flat.

Post by **vk6hgr** » Thu Aug 02, 2007 12:30 pm

CHEV4EVR wrote: You can tell by listening to a vehicle transmissions as to whether they are using analogue or digital, it is quite distinctive.

Sounds like a bad GSM mobile call. Audio quality is very mediocre.

CHEV4EVR · Post by **CHEV4EVR** » Thu Aug 02, 2007 9:29 pm

and the portables can sometime sound like you are talking in a toilet bowl. Mind you I can live with the distortion given the repeater range and lack of crackle.

Post by **vk6hgr** » Thu Aug 02, 2007 9:31 pm

CHEV4EVR wrote:and the portables can sometime sound like you are talking in a toilet bowl. Mind you I can live with the distortion given the repeater range and lack of crackle.

I'm going to have to dust off the old WARSUG press pass and arrange me a demonstration one of these days...

CHEV4EVR · Post by **CHEV4EVR** » Thu Aug 02, 2007 9:34 pm

I would give you a demo but unfortunatley I have moved to an area that is not "online" yet. If you don't get a look shortly pm me and I will see what I can organise.

Post by **vk6hgr** » Thu Aug 02, 2007 9:35 pm

CHEV4EVR wrote:I would give you a demo but unfortunatley I have moved to an area that is not "online" yet. If you don't get a look shortly pm me and I will see what I can organise.

Awesome, Thanks!

Ausrob · Post by **Ausrob** » Sun Aug 05, 2007 6:37 pm

Is the digital radio encyrpted or can we still listen in?

Post by **Tyranus** » Sun Aug 05, 2007 6:55 pm

It's digital, so your scanner won't pick it up. Because they've made it digital wouldn't be too much harder to encrypt it, so they're probably doing that too.

spartacus · Post by **spartacus** » Sun Aug 05, 2007 7:15 pm

but what if they didn't (which is unlikely) encrypyt it? Then you should be able to listen in with a digital radio then?

Ausrob · Post by **Ausrob** » Sun Aug 05, 2007 7:22 pm

Tyranus wrote:It's digital, so your scanner won't pick it up. Because they've made it digital wouldn't be too much harder to encrypt it, so they're probably doing that too.

Sorry that wasn't structured correctly. It's my understanding that the Uniden UBCD996T and UBCD396T can listen in on digital radio that are unencyrpted.

But I've read I'm not sure if it's here or elsewhere that each digital handset WAPOL is using needs to be married to the base station to communicate.

Post by **Tyranus** » Sun Aug 05, 2007 7:33 pm

Ok fair call yes a digital scanner won't pick it up.

If they have to be married to a base station then:
a) the base station is going to break the law, about being married to more than 1!

b) sounds like they're going to use digital certificates/tokens in the radios, that will instruct the radio on how to lock the packet so that only the base and other handsets can open it, this would then make it possible to easily change if a handset gets stolen, simply have docking stations at the desk, or in the car which can update with a new certificate, and for the car radios, it can just be pushed out through the TADIS. Bikes they'd have to work through a slightly different system.
Then once everyone has the new certificate, just block the old certificate and presto someone has a useless police radio, unless they can dock it at a police station. But then they'll probably have it as a recorded bad serial, so it won't update, and if anything will pretend to update, but will notify someone that it's plugged in somewhere.

Sorry, my inner geek just couldn't resist.

spartacus · Post by **spartacus** » Mon Aug 06, 2007 6:17 pm

that dosn't sound geekish,
it's a very structured answer to the question

Nick · Post by **Nick** » Mon Aug 06, 2007 6:38 pm

The encryption has nothing to do with tadis. All the motorola radio's have OTAR over the air rekeying of the encrytion code. This code is itself is encrypted with in the digital packet that is sent to the radio with the encrypted audio and channel control data. It would be extremely difficult to decrypt this information which is why it was chosen. The radio is keyed at the start with the callsign, serial number and other data then it is able to be controlled over the air.