EDACS Provoice

[emtLarmy15]

With most of the EDACS capable GRE/RS scanners, you can read digital talkgroup ID's. I tried it my self. I work for a local PD that uses analog and pro-voice. Most com's are on analog, but we switch to pro-voice when we wanna "just talk" or have info we don't want everyone knowing.

Anyway, I keyed my radio on one of our provoice t/g's and had one of my scanners on the control chan for the system and it did come up with the proper dec ID for the t/g....though the scanner does ignore it and will not put you on the voice freq (which would be pointless anyway)....

Just thought I would add that in

 

[Thayne]

Cool. To me that means it would be easier than maybe we all thought to Decode provoice, since the talkgroup info is being decoded.
That must mean that bit of data that means provoice transmissions could be used to turn on the provoice vocoder ??

 

[kikito]

MaxTracker said:

I am thinking, Uniden will devolope a ProVoice friendly scanner soon, they already were first to do Open Sky.

When did Uniden developed an Open Sky scanner? or is this an exclusive radio for M/A Com customers? Just asking....

 

[12VoltInstaller]

HERE YOU GO ROB.......

Whitney McDowell
Account Executive
Ogilvy Public Relations Worldwide
303.634.2635 Voice
whitney.mcdowell@ogilvypr.com

Figured this my be the best person to bug. Let me know if you think not.

Corporate Headquarters
GRE America, Inc
425 Harbor Blvd.
Belmont, CA. 94002

Sales Department Ph: (650) 591-1400
Fax: (650) 591-2001
Toll Free : 800-233-5973 Email: sales@greamerica.com
Radio Modem Support
Support Form Email: techsupport@greamerica.com

Scanner Amps & Accessories
Support Form Email: superamp@greamerica.com

this is the one off japans site for GRE:

mailto:gre-mail@gre.co.jp

I just sent one to GRE asking when they might have something.

 

[hosehead88]

Re: EDACS-ProVoice

I am thinking, Uniden will devolope a ProVoice friendly scanner soon, they already were first to do Open Sky.

Since I have not been paying attention lately, can you enlighten me as to which scanner will track OpenSky?

I was under the impression that such a beast did not exist.

Thanks,

KL

 

[Voyager]

Re: Re: EDACS-ProVoice

Since I have not been paying attention lately, can you enlighten me as to which scanner will track OpenSky?

I was under the impression that such a beast did not exist.

Thanks,

KL

It doesn't... yet.

Someone is hallucinating.

Joe M.

 

[Thayne]

Provoice revisited

I have verified that GRE scanners will show Provoice TG's; My 785D just ignores them completely.
I have been researching DSP IC's on the internet; (A lot of it is WAY over my head)
If there are any experts out there to point me in the right direction as far as a DSP chip that would demodulate provoice, I was going to use E trunk to drive a PRO-2052, the send the Disc tap output of it to the hoped for DSP; the on to an audio amp of course. (Just for kicks--I have a lot of time on my hands for the next month)

I know there will be a scanner out sometime; it seems to me that a good way to go would be to take a unit such as a PRO-96 or 796-D and make it customer configurable as far as the various flavors needed by the public.

Don't they save a lot of money by not changing the basic radio from model to model?

Any thoughts??

 

[rdale]

How did you verify it? My Pro96 skips all ProVoice talkgroup ID's... Are you hearing the data signal when it activates?

 

[Thayne]

I put a pro-2067 on the EDACS CC; and at the same time the 785-D is on. The display on the 2067 keeps flashing multiple talkgroups (while the 785D is silent) Some of the talkgroups match what is posted about the new Aurora system for police TAC groups. Early this AM the system was lightly loaded, the 785D heard the analog fire disp simultaneously as It showed on the 2067 display. (The 785 defaults to AFS so I converted that to decimal to make the comparison)
I will try it on the 96, I just didn't want to change the programming--I don't doubt you are right about the 96. I would have thought it would be the same type of scheme in both but I guess not.

Any thoughts about my idea? (xcept too much time on my hands)

 

[rdale]

Ahh - I've not tried letting it sit on the control channel. I was referring to scanning in 'open' mode, I'll give your idea a shot.

- Rob

 

[hosehead88]

Pardon my ignorance, again....but is ProVoice the same as OpenSky?

Thanks,

KL

FTM-PTB

 

[rdale]

No, PV is the 'digital' side of EDACS. OpenSky is a completely separate and unscannable all-digital system.

- Rob

 

[scanfan03]

Re: Provoice revisited

Don't they save a lot of money by not changing the basic radio from model to model?

Any thoughts??

That's how they gain their money. You buy a new scanner for $350 from them, then a new scanner with new features comes out that costs $500 and you decide to buy it. They just gained $850.

 

[Thayne]

I was thinking more in terms of how GM uses the same platforms for many Vehicles; Like Tahoes and Escalades. They save by using the same chassis components. The uniden 780 785D and 796 use the same basic layout and they sure keep the price up--but when the PRO-96 came out they included the card for less $$
They should make a card for provoice, just like they did for APCO-25.

It would be cool if some hobbyist beat them to having a provoice setup.

 

[emtLarmy15]

Yes the GRE scanners will display the talkgroup ID on the control channel...I know this cause I tried it a while back using my provoice radio and pro 93 scanner...this is all true because pro-voice uses the same EDACS control channel, so nothing is different there, its just the voice channel thats different.

Chris

 

[W4KRR]

The State of Florida's new ProVoice system supposedly has an encrypted control channel. Monitoring of such a system will never happen, even if there were a ProVoice capable scanner.

 

[rdale]

It's not encrypted -- it's called EDACS System Key (ESK) and has been figured out by posters on this forum. Do a quick search for ESK and you'll be able to read up on it.

 

[Voyager]

It's not encrypted -- it's called EDACS System Key (ESK) and has been figured out by posters on this forum.

That wouldn't matter. If it's encrypted at all - even using the most simple method (call it a key), it's illegal to decrypt, thus illegal to sell in a scanner.

Yes, users can do a lot more than a manufacturer can sell.

Joe M.

 

[SCPD]

The purpose of ESK is to make the EDACS control channel more resilient to false decodes caused by another distant EDACS system on the same channel. It really has nothing to do with encryption.

-rick

 

[Voyager]

The purpose of ESK is to make the EDACS control channel more resilient to false decodes caused by another distant EDACS system on the same channel. It really has nothing to do with encryption.

-rick

Well, it all comes down to interpretation. Would the FCC consider the key to be a form of encryption (regardless of how it was intended)? I'll use this as an example: Many manufacturers elected to not include I-call because its function was too closely related to a private phone call and they didn't want to violate any FCC Cellular-based rules. (is there any expectation of privacy using an I-call?)

Regardless of how simple the 'encryption', the origin or reasoning behind its implimentation, or how many possible combinations (keys) there are, it could be considered to be encrypted or coded, and protected under the encryption laws.

LTR uses a code to separate two systems (0 and 1), but it is part of the same code and does not alter the datastream at all (beyond that single bit). As I understand it (and I could be wrong), ESK actually changes the code (datastream) by using it as a key to decode the stream. This is a big difference. The ESK seems to much more closely resemble encryption - where you need a key to put the datastream back in the base form to recover the voice data (or CC data). Again, whether there are 16 zillion, or two possible key combinations is only a difference of magnitude. Where do you draw the line? (The FCC draws it as anything beyond a standard stream - no keys needed - like P-25)

Of course, should M/A-Com elect to authorize a manufacturer to use the code, and decrypt their control channel, this would all be a moot point. Now, who really can authorize the decryption? The manufacturer, or does it have to come from the *licensee*!

Voice inversion is a very simple scrambling method, and an 8-year-old can crack it. Still, it is illegal to do. It's amazing that one manufacturer can legaly sell a voice inversion option for their scanners. (or maybe it is illegal to sell that option in the USA)

Not trying to debate the issue - just bringing up some alternative points of view. After all, the FCC's 'opinion' is the only one that matters.

Joe M.