The pro's and con's of police digital radio's.

[CCHLLM]

The argument that digital formats equate "hiding" is the same kind of ignorant nonsense that some amateur radio operators spouted when we first started adding CTCSS to some repeater receivers in order to keep co-channel interference and some noise out of the repeater. In spite of announcements recorded in the station ID audio that gave the CTCSS frequency, we who did so were summarily criticized for "closing" the repeaters and inhibiting the basic "freedoms" of amateur radio.

The airwaves are public property. That means that as far as receiving goes, the spectrum is open to anyone who can come up with the technology to listen to what's being broadcast except where prohibited by law. Furthermore, the police communications entities are not the ones who started the digital revolution in the first place, and digital formats were never created to "hide" anything. Digital formats are created to promote efficient spectrum use.

My pet peeve? Lack of EDACS digital formats monitorability (new word?) Unlike P25 technology, EDACS digital isn't routinely monitorable because the manufacturer simply decided not to license the technology to anyone outside of the proprietary manufacturing group, not because of any attempt to hide anything. You are perfectly free to attempt to reverse engineer a way to listen, but you'll be bucking proprietary engineering and software copyright laws, not some "secrecy" conspiracy, so be prepared to pay for that effort.

I don't like encryption either because it cramps my listening, but there are certain aspects of secure operations, messaging, and evidence gathering during investigations and prosecutions that are, by law, none of your business until the cases are adjudicated and the evidence and disposition becomes, by law, public information.

 

[n1das]

I read it again, but I saw the English version so that may differ from what you are working with.

It says that the police cannot EXPECT privacy when they transmit in the open and scanner listeners hear. It does not say (anywhere that I can find) that the public has a RIGHT to hear all police transmissions.

X2. What rdale said. While we technically don't have RIGHT to listen, we don't necessarily have to AVOID listening either. Not having a RIGHT to listen and having to AVOID listening are two different things.

 

[n5ims]

My pet peeve? Lack of EDACS monitorability (new word?) Unlike P25 technology, EDACS isn't routinely monitorable because the manufacturer simply decided not to license the technology to anyone outside of the proprietary manufacturing group, not because of any attempt to hide anything. You are perfectly free to attempt to reverse engineer a way to listen, but you'll be bucking proprietary engineering and software copyright laws, so be prepared to pay for that effort.

I think you're talking about ProVoice or OpenSky, not EDACS. Many scanners will monitor EDACS systems, even the old RS Pro-95 (http://wiki.radioreference.com/index.php/Pro-95):

RR System Compatibility
This scanner is compatible with the following Trunking System Types and System Voices used in the RadioReference Database, of course you must verify that the scanner will cover the appropriate frequency range:

System Types:
Motorola Type I
Motorola Type II
Motorola Type IIi Hybrid
Motorola Type II Smartnet
Motorola Type II Smartzone
Motorola Type II Smartzone Omnilink
EDACS Standard (Wide)
EDACS Standard Networked

 

[Astrak]

The argument that digital formats equate "hiding" is the same kind of ignorant nonsense that some amateur radio operators spouted when we first started adding CTCSS to the receivers of some amateur repeaters in order to keep some types of interference out of the repeater. In spite of announcements recorded in the station ID audio that gave the CTCSS frequency, we who did so were summarily criticized for "closing" the repeaters and inhibiting the basic "freedoms" of amateur radio.

The airwaves are public property. That means that as far as receiving goes, the spectrum is open to anyone who can come up with the technology to listen to what's being broadcast except where prohibited by law. Furthermore, the police communications entities are not the ones who started the digital revolution in the first place, and digital formats were never created to "hide" anything. Digital formats are created to promote efficient spectrum use.

My pet peeve? Lack of EDACS monitorability (new word?) Unlike P25 technology, EDACS isn't routinely monitorable because the manufacturer simply decided not to license the technology to anyone outside of the proprietary manufacturing group, not because of any attempt to hide anything. You are perfectly free to attempt to reverse engineer a way to listen, but you'll be bucking proprietary engineering and software copyright laws, so be prepared to pay for that effort.

I don't like encryption either because it cramps my listening, but there are certain aspects of evidence gathering during investigations and prosecutions that are, by law, none of your business until the cases are adjudicated and the evidence and disposition becomes, by law, public information.

Ummm scanners have been able to track and monitor EDACS for years now. Do you mean monitor ProVoice EDACS? Have you tried DSD it will let you hear ProVoice.

 

[CCHLLM]

OK guys, forgive me for not stating that EDACS digital formats are my pet peeve in monitorability. After 40 years in the two-way radio business, I am extremely familiar with EDACS. So, ummmmm, I'll correct it if I can.

UPDATE: previous post somewhat corrected. Did I get it right this time?

I'm aware of DSD but have not tried it simply because there are not enough public safety entities in NC on ProVoice that I need to listen to or spend more money to listen to. It's a peeve in principal that the proprietor isn't willing to make it available like P25, not because I can't monitor it.

OK, truth time: I loved GE Communications gear and still have several fine examples of it in operation. It was the boarding of the Ericsson train to Hell and Mediocrity that I'm still mad about, Ha Ha!!

 

[gewecke]

The title of this thread sure is misleading!

Thread title: The pro's and con's of police digital radio's.
Corrected thread title: The pros and cons of police digital radios.

Pros:
-----
- Clear, noise-free digital audio.
- Able to operate more narrowband compared to analog-only FM radios.
- More usable all the way down to the SINAD threshold when dealing with weak signals.
- Supports high speed data capabilities in addition to voice data. Whether it's voice, video, or other data being transmitted, it doesn't matter provided the data can be represented as digital data.
- Offers encryption capabilities for secure communications when needed. Audio quality doesn't suffer compared to analog scrambling systems.
- Able to communicate in analog mode to work with older analog-only legacy radio systems.

Cons:
-----
- Radios are generally more expensive than analog-only radios.
- Locked into using a particular digital standard to communicate in digital mode(s).
- Analog is already interoperable.

Not in our case,where we have one dept. who can NOT talk to the rest of the county because they are digital,but this is changing.
n9zas

 

[mikewazowski]

Not in our case,where we have one dept. who can NOT talk to the rest of the county because they are digital,but this is changing.
n9zas

I think most people forget that digital radios will do analog as well.

If they're that concerned about mutual aid, then setup an analog channel.

 

[zerg901]

1. "Clear, noise-free digital audio." vs "you went digital". "More narrowband" - 8K10 vs 11K2? More useable SINAD? Vs "fall off cliff" syndrome.

2. England police went to all encrypted radios 5 years ago. I dont recall reading any reports that their murder rate dropped to zero because of the encrypted radios. I wonder if the rate of murders of police, or murders by police, has risen or fallen. (I wonder how many scanners Saddam had?)

3. Analog scanner - $100. Digital scanner - $500.

Peter sz

 

[RKG]

I'm familiar with the FCC Narrowbanding requirement which does NOT require digital. Is Your Part 90 UHF or VHF Radio or SCADA System Narrowband Ready? Where has the FCC stated a requirement for "very narrow band" that only digital is capable of?

That may be the case for some digital systems but not necessarily all of them. You must not have had the pleasure (or rather displeasure) of listening to OpenSky. :roll:

As far as Moonbounce's post, if he wants to monitor unencrypted digital then of course he will have to pony up the extra $$ for a new scanner. If his concern is encrypted transmissions, he's out of luck for now.

Actually, what the poster may be referring to is the FCC's ambition (not yet legislated into a mandate) to achive so-called 6.25 KHz channel deployment.

The problem is that no one has figured out how to transmit 3 KHz analog audio on an FM channel that is deviation limited to +/- 1.25 KHz and emission limited to something on the order of 5 KHz.

Even achieving 6.25 KHz channels with digital is difficult; the funny sounding audio on most CAI systems derives, ultimately, from the limited headroom one has for data. Motorola's grand idea was to sell MotoTRBO, using two simultaneous TDMA audio channels over a 12.5 KHz data channel, as "6.25 equivalent." So far, the FCC hasn't been buying it.

 

[jackj]

Digital isn't as efficient at transmitting voice info as analog. Analog transmission is copyable at much higher noise levels than digital. Digital, even with compression, requires more band width to transmit the same info because of the necessary digital overhead.

None of the above means that digital shouldn't be used, I point it out because the arguments being made here are mistaken. It is easier to add services to digital like Mobile Data Terminals which can NOT be added to analog (it has to be a separate stand-along system). Digital communications is the wave of the future and, if you want to listen in, you must spend some money. You didn't get your analog scanner for free after all.

Also, the job of the police in the USofA isn't to protect the citizens. It is to investigate, solve crimes, enforce the law and take reports. You, not the government, are responsible for your own protection.

 

[GB1952]

the digital reception will work just as well as,if you have the proper antenna for it,i have replaced all of my antennas with digital reception antennas and they work very well at 30ft.

 

[mypoppa60]

All they ever use encryption for is to check to see who does not want onions on their hotdogs!

 

[Astrak]

OK guys, forgive me for not stating that EDACS digital formats are my pet peeve in monitorability. After 40 years in the two-way radio business, I am extremely familiar with EDACS. So, ummmmm, I'll correct it if I can.

UPDATE: previous post somewhat corrected. Did I get it right this time?

I'm aware of DSD but have not tried it simply because there are not enough public safety entities in NC on ProVoice that I need to listen to or spend more money to listen to. It's a peeve in principal that the proprietor isn't willing to make it available like P25, not because I can't monitor it.

OK, truth time: I loved GE Communications gear and still have several fine examples of it in operation. It was the boarding of the Ericsson train to Hell and Mediocrity that I'm still mad about, Ha Ha!!

Oh ok that makes sense, I think I just misunderstood your original post.

 

[radioman2001]

I kinda agree with jackj, but obviously you havn't seen the aftermath of when a civilian protects himself, making the police look like fools or the fact they they feel you did THEIR job. The government then prosecutes you.

 

[CCHLLM]

Oh ok that makes sense, I think I just misunderstood your original post.

I tend to become extremely misunderstoodable at that hour of the day, and I definitely left out the operative word >>> digital. I even fell asleep during the exchange and missed the FireFox update that occurred while I snoozed. :b

Anyway, I agree with the premise of enhancing spectrum efficiency through digital, but while data and messaging may be a good fit in the current digital narrowband technologies, human speech in analog format is still the preferred method of discourse because it is the natural format, and as posted above, the voice side in digital tends to suffer in less than optimal conditions. I remember the change from 30 KHz to 15 KHz "narrowband" frequency channel spacing, and the audio quality suffered from that narrowing, too. Throw in current digital audio characteristics coupled with even narrower bandwidth and it becomes very difficult to make the audio sound "right" to the human ear.

 

[mikewazowski]

the digital reception will work just as well as,if you have the proper antenna for it,i have replaced all of my antennas with digital reception antennas and they work very well at 30ft.

:lol:

 

[OemUser]

Omg.....

the digital reception will work just as well as,if you have the proper antenna for it,i have replaced all of my antennas with digital reception antennas and they work very well at 30ft.

I was afraid that the sales clerk at the 5th wheel truck stop was lying to me about the antennas that she sold me.....but I'm glad to see that she wasn't....she told me that the antennas that I purchased would decode any digital encryption of any sort for any signal that the antennas would receive....she called them a stealth antenna....didn't matter what kind of a receiver that I had....these digital antennas would let me hear all......in the clear. She also indicated that these antennas had something called a "noisegate" that would protect the electronics in my radio from all of the viruses that the hackers are turning loose on the world....

Ah, whatever happened to the good old days of crystal 23 channel cb radios?

 

[neondesert]

I was afraid that the sales clerk at the 5th wheel truck stop was lying to me about the antennas that she sold me.....but I'm glad to see that she wasn't....she told me that the antennas that I purchased would decode any digital encryption of any sort for any signal that the antennas would receive....she called them a stealth antenna....didn't matter what kind of a receiver that I had....these digital antennas would let me hear all......in the clear. She also indicated that these antennas had something called a "noisegate" that would protect the electronics in my radio from all of the viruses that the hackers are turning loose on the world....

That sales clerk didn't have a second job working at Radio Shack by any chance did they?!? :lol:

 

[jackj]

Hmmmm!

the digital reception will work just as well as,if you have the proper antenna for it,i have replaced all of my antennas with digital reception antennas and they work very well at 30ft.

I would be interested in knowing the difference between a digital and an analog antenna please?

 

[rdale]

He is joking.