• Effective immediately we will be deleting, without notice, any negative threads or posts that deal with the use of encryption and streaming of scanner audio.

    We've noticed a huge increase in rants and negative posts that revolve around agencies going to encryption due to the broadcasting of scanner audio on the internet. It's now worn out and continues to be the same recycled rants. These rants hijack the threads and derail the conversation. They no longer have a place anywhere on this forum other than in the designated threads in the Rants forum in the Tavern.

    If you violate these guidelines your post will be deleted without notice and an infraction will be issued. We are not against discussion of this issue. You just need to do it in the right place. For example:
    https://forums.radioreference.com/rants/224104-official-thread-live-audio-feeds-scanners-wait-encryption.html

San Antonio ProVoice

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Cowthief

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Hello.

Yes, you can listen to ProVoice, that is the good news,
You will need a ProVoice radio and not a scanner, and some connection to just about any media outlet, that is the bad news.
The system was installed by Dailey-Wells communications.
They are located in the same parking lot as the Bexar county red cross.
So, what about it?
The media has some sort of arrangement to monitor the system, police, fire, the whole thing.
There are "channels" that are not 'open', but there is a way around that.
The radios cost something between 2 and 3 grand, that is the really bad part.
I have done a demo with Mr. Richard Wells in where I showed a totally unblocked talkie, all keys were loaded and working on the system.
It is also a voilation of federal law to do this without prior clearance, so there will be no discussion that could violate federal law.
 

bigbluemsp

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Cowthief said:
Hello.

Yes, you can listen to ProVoice, that is the good news,
You will need a ProVoice radio and not a scanner, and some connection to just about any media outlet, that is the bad news.
The system was installed by Dailey-Wells communications.
They are located in the same parking lot as the Bexar county red cross.
So, what about it?
The media has some sort of arrangement to monitor the system, police, fire, the whole thing.
There are "channels" that are not 'open', but there is a way around that.
The radios cost something between 2 and 3 grand, that is the really bad part.
I have done a demo with Mr. Richard Wells in where I showed a totally unblocked talkie, all keys were loaded and working on the system.
It is also a voilation of federal law to do this without prior clearance, so there will be no discussion that could violate federal law.


Boss this post makes no sense. Also if you are offering this radio then wouldnt it be a federal violation?
 

Cowthief

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San Antonio.

Hello.

Read the post.
The media i.e. the "Press" can get a ProVoice radio.
That is just about any media outlet there is, from your local newspaper, including greensheet, to any of the dozen radio stations to people who do "news" on public access cable TV, 'Media' is quite open, there is no requirement to be a member of the media.
With that said, this being the only 100% legal way to get such a radio, you are on your own.
The second part, the radio that the media is provided, after you buy it, is locked to a limited number of talkgroups "channels".
If you elect to alter the programming of the radio, you could be in violation of federal law.
So, to recap.
Find someone in the media who will sponser you to buy a radio.
If you monkey with the software, keep it to yourself.
 

loumaag

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Cowthief,

I understand what you are trying to get across; however, your facts are clouded by what the Public Safety folks in SA would like you to believe. Here are the facts:

  • Anyone can buy a ProVoice capable radio and if you can get it programmed, you can listen to ProVoice. You need no one's permission. The radios are sold on a daily basis on eBay and other places. Programming can be had from several sources including spending the money on the software yourself.
  • SA has used a method of coding the Control Channel called "ESK"; which stands (I think) for Encrypted System Key. It is in fact not a system key nor is it encrypted. ESK is a marketing ploy to make chumps out of the people paying extra for it as a means to foil people with the available ProVoice radios; it is merely swapping an offset in the data stream. I repeat, no key, no encryption.
  • As muddy mudskipper mentioned the only problem with monitoring the SA ProVoice system with a radio is in changing the above mentioned ESK value via software.
As others have said, this is old news and nothing new has been added. I will tell you that there are people monitoring the SA Public Safety broadcasts that are not "media" affiliated and they are not violating any law, rule, or standard.
 
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ESK = EDACS System Key.

at one point, MA/COM considered dumping the XOR scheme implemented in ESK and shooting for a weak DES scheme instead. i think it had something to do with Lindsay and others figuring out the XOR scheme...

as far as i can tell, they are still using a XOR and there are about 254 known ESK keys available, although pretty much the same one remains in use in most deployed systems.

if ESK becomes a Programmer-able feature, i'd certainly want to know. but as far as i can discern, it still requires an ESK smart card (think of it as a dongle) + the Programmer software to program the latest Provoice radios to receive the SA system.
 

SCPD

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Here is my understanding of ESK and Site-Pro as it pertains to programming an actual radio.

[ Someone please shoot this down if you see any errors. ]

Prior to ESK and SitePro systems, you only needed software and radio. EDACS software did not require a programming key like Motorola CPS and RSS - at least not until ESK and SitePro. MA/COM only needed to change the control channel just enough to prevent radios with pre-ESK firmware from operating on an ESK enabled system.

That prevents rogue radios from attempting to use the network. It also prevents receive-only programmed radios from tracking voice calls by talkgroup. My understanding is that - with ESK turned ON - only an ESK enabled radio will work. The ESK enabled radio will only accept programming from software with the appropriate key.

As a side note - all of this fuss over Provoice is just nuts. With a little effort the scanner manufacturers could have included ProVoice formatted IMBE along with P25 IMBE in every radio that supports P25 and EDACS. This would give folks what they need without the added liability of accidentally transmitting on a public safety system.

-rick
 
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rfmobile said:
all of this fuss over Provoice is just nuts.

-rick
agreed.

let's also not forget that you can scan the frequencies of an ESK system conventionally and still more-or-less follow a conversation. whether this is in Analog mode (with a scanner) or in Provoice mode (with a real Provoice radio). so from a security standpoint, it doesn't prevent monitoring.

think of how you used to monitor a trunked radio system in the pre-trunking days of scanners.

as for ESK preventing rogue radios from acquiring the system, well sure. but i think MA/COM originally intended it to segregate unique EDACS systems that had similar site ID's. as in the case of San Antonio and Corpus Christi. two disparate systems that tended to clash with each other when tropospheric ducting conditions were right. which was just about every morning in the Spring and Summer.

ironically, i think of how modern scanners now decode the Motorola System ID as if it was nothing. definitely no concern as to it being a security feature. it wouldn't be too big a leap to implement this with an EDACS ESK system.

personally, i believe the only thing in the way of this development is the fact that most EDACS ESK radio networks deployed across the US are in full-time Provoice mode and that complicates matters for scanner manufacturers. no one really wants to step on MA/COM's IMBE protocol, but ESK is a non-copyrighted process that could easily be implemented in the next release of scanner. it's a messy situation.
 

rdale

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rfmobile said:
With a little effort the scanner manufacturers could have included ProVoice formatted IMBE along with P25 IMBE in every radio that supports P25 and EDACS.
Don't know about the rest of your post - but this one needs to be shot down and cremated. Scanner makers want to include ProVoice in their digital radios - but MA said no. And since they hold the patent, there's no way around it. Refer to the "ProVoice scanner" sticky.

- Rob
 

SCPD

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mudskipguy said:
but i think MA/COM originally intended it to segregate unique EDACS systems that had similar site ID's. as in the case of San Antonio and Corpus Christi. two disparate systems that tended to clash with each other when tropospheric ducting conditions were right. which was just about every morning in the Spring and Summer.
My thinking has shifted on this - although ESK does help - but only if the distant system is a non-ESK system. As more ESK systems are deployed - you're back to the same problem.

no one really wants to step on MA/COM's IMBE protocol, but ESK is a non-copyrighted process that could easily be implemented in the next release of scanner. it's a messy situation.
That's part of my point - IMBE isn't MA/COM's property. It belongs to someone else ... see below.

rdale said:
Don't know about the rest of your post - but this one needs to be shot down and cremated. Scanner makers want to include ProVoice in their digital radios - but MA said no. And since they hold the patent, there's no way around it. Refer to the "ProVoice scanner" sticky.
I'm wondering if that conversation actually took place. Anyone that actually knows - please speak up. Also, the patent on IMBE is held by DVSI, not MA/COM (or GE or Tyco or whatever). I don't see anything in the way ProVoice "packages" the IMBE data that is patentable. If there is a ProVoice patent - please point that out. The data is there. The P25 radios already have a licensed IMBE decoder inside. Someone is slacking on their R&D.

-rick
 

rdale

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"Someone is slacking on their R&D."

Can't find the sticky right now - do a search and/or LB can pull out the thread for us. No need to again rehash this, but the point is your assumptions are all wrong.
 

scannerfreak

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Rick, If I remember correctly, they use the same IMBE vocoder, but MA/COM sends the data in a proprietary way, which makes it patentable.. This is the thread that I think they are talking about..Also, Read this one It has very good info..

blantonl said:
The framing is middle of the road... there is play in this process.

The Motorola control channel was patented by Motorola.

Same with EDACS....

We have scanners for both now.

ProVoice uses the IMBE vocoder - Uniden, RS, and AOR all have licenses.

I think from a *decoding* perspective, all that needs to happen is someone reverse-engineer the gmsk framing process for provoice. Uniden and Radio Shack can run into the valley with this information... apply their DVSI license to the decoded frames, and sell a ProVoice scanner.

Speculation, however, it's nothing different then figuring out the framing process for the Motorola control chanel, the EDACS, and on and on....

-Lb
And....

blantonl said:
Just to clarify.

ProVoice and APCO-25 use the EXACT SAME IMBE VOCODER. The same one. It works the same. The license is the same. It is the same vocoder. Did I mention that they are the same vocoder? It is the same.

The differences between the two digital voice formats is how the information is transmitted over the air (modulated).

The vocoder does nothing more than convert analog audio into a compressed stream of 1s and 0s. That SAME PROCESS happens for P25 systems, and for ProVoice systems. However, those 1s and 0s must be transmitted over the air. This is where the difference between the P25 standard and ProVoice differ.

MA/COM believes they have the superior solution to transmitting the vocoder information over the air. Their solution for doing this is proprietary. The Project 25 standard believes they have the superior solution -- their standard is there for all to see in the TIA documents.
 
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SCPD

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All right guys - rdale and scanner_freak - you're both quoting the RR forums. I've read the linked conversations above. All I see are folks either making guesses or repeating someone else's guesses. The sticky to which you refer is based on assumptions. I am challenging those assumptions. I'm not doing this on whim. I've got hard data that says otherwise.

That's right, I'm not playing fair - I've cards that I'm not showing.

:evil:

Does anyone have anything that can slam-dunk confirm or contradict those assumptions?

-rick
 

scannerfreak

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Nope, not I :) Was merely posting the info Rob was talking about, and showing you where I found what I was refering to when I made the statement above.

I will be the first to tell you, I know absolutley nothing about Pro-Voice. I do not have a system anywhere close to my local...If those posts wouldn't have been posted by Lindsay, I would not have extracted them specificly from those threads :)

I hope for all my fellow scanner heads in Pro Voice land that something can be figured out someday :)
 
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