Neat find in Edmonton

[Jay911]

You folks may recall in the summer, I put a bunch of evident trunk systems in the Alberta DB and identified them as best I could, from monitoring and guessing.

Someone has pointed out that the one I had in Edmonton for "Communications Group Edmonton" was no longer (if it ever was at all) an MPT-1327 system. They provided me with an audio sample which sounded curiously like static (or DES voice) with an APCO P25 "repeater squelch tail" tacked on the end. Those of you who have ever monitored 753f with an analog scanner and heard the end of a police transmission will know what I mean.. the last 2 or 3 seconds, where the system is transmitting full quiet "dead air" (repeater tail) sounds quite different than the part with spoken voice.

I did some searching and comparing - the Digital Modes & Samples page had nothing to offer, and other sites were just as unforthcoming, if that's a word. I did figure it out, though, from another post on this actual site.

The 'system', if you can call it that - seems to be just one frequency for now - is the new MotoTRBO standard, which is essentially a completely different digital format than the P25/IMBE/Provoice currently in use around the province. MotoTRBO is what's called TDMA (Time Division Multiplex Access, if I remember it right) which is most like cellphones or iDEN systems, in that multiple audio signals are carried on one stream. That's a very simplified explanation, but the gist of it is, you can't monitor it at present. (And if the same thing holds true for MotoTRBO as it does for iDEN, you likely won't see a scanner any time soon for it, because the hardware needed to handle such a signal is far too precise and complex to affordably include in a scanner.)

I moved all the frequencies for CGE into the conventional part of the database. Since we don't have a "MotoTRBO" modulation setting right now (the only options are AM, FM, P25, and Data), I chose P25, just to identify the channel as non-analog. The other ones I'm not sure about - my source did mention it sounded like they had LTR control bursts on them.

Now I feel the urge to drive down into the south of Calgary and snoop for Communications Group Calgary's signals.. see if they changed over from their own MPT system..

 

[DaveH]

Since we don't have a "MotoTRBO" modulation setting right now (the only options are AM, FM, P25, and Data), I chose P25, just to identify the channel as non-analog.

Not a good idea methinks. People will wonder (and complain) why their new
P25 scanner doesn't work on the frequency. Better to classify as iDEN being as
it's closer to that, and like iDEN can't be monitored by anything other than
specialized equipment.

Dave

 

[Jay911]

There isn't an iDEN setting for single channel non-trunk systems.

I'm still trying to decide if it counts as a 'trunk'.. the fact that it carries multiple audio paths on a single frequency may mean it does.

Eventually (hopefully) we'll have a MotoTRBO designation in the DB.

 

[BC_Scan]

Yes regretably in the West there are some prime (ok good) listening going silent as they fall prey to Motobro systems, here in Vancouver we have lost City of NEw West (Pub works) only , but the biggy was, Port of Vancouver,
now for the next killer ICom & Kenwood have ganged up on a new digital system marketed towards many different users called MN?? (sorry I did not write it down) , boasting 50 % radio range signal improvement on digital and a whole whack of extra features .
It will become the radio killer should it take off fully, it was according to the brochure I saw a proprietary system (no ltr, or Edacs, mpt etc) so another hurdle the scanner manufacturers would have to buy into if they would want us to listen into !
Will try and get more info on what I saw (a quick check of Kenwoods site did not reveal yet)

 

[SCPD]

You folks may recall in the summer, I put a bunch of evident trunk systems in the Alberta DB and identified them as best I could, from monitoring and guessing.

Someone has pointed out that the one I had in Edmonton for "Communications Group Edmonton" was no longer (if it ever was at all) an MPT-1327 system. They provided me with an audio sample which sounded curiously like static (or DES voice) with an APCO P25 "repeater squelch tail" tacked on the end. Those of you who have ever monitored 753f with an analog scanner and heard the end of a police transmission will know what I mean.. the last 2 or 3 seconds, where the system is transmitting full quiet "dead air" (repeater tail) sounds quite different than the part with spoken voice.

I did some searching and comparing - the Digital Modes & Samples page had nothing to offer, and other sites were just as unforthcoming, if that's a word. I did figure it out, though, from another post on this actual site.

The 'system', if you can call it that - seems to be just one frequency for now - is the new MotoTRBO standard, which is essentially a completely different digital format than the P25/IMBE/Provoice currently in use around the province. MotoTRBO is what's called TDMA (Time Division Multiplex Access, if I remember it right) which is most like cellphones or iDEN systems, in that multiple audio signals are carried on one stream. That's a very simplified explanation, but the gist of it is, you can't monitor it at present. (And if the same thing holds true for MotoTRBO as it does for iDEN, you likely won't see a scanner any time soon for it, because the hardware needed to handle such a signal is far too precise and complex to affordably include in a scanner.)

I moved all the frequencies for CGE into the conventional part of the database. Since we don't have a "MotoTRBO" modulation setting right now (the only options are AM, FM, P25, and Data), I chose P25, just to identify the channel as non-analog. The other ones I'm not sure about - my source did mention it sounded like they had LTR control bursts on them.

Now I feel the urge to drive down into the south of Calgary and snoop for Communications Group Calgary's signals.. see if they changed over from their own MPT system..

I can see a TDMA scanner in the near future. TDMA is Open Protocol, why not incorporate it in a scanner? Just 5 years ago they said we would never see a Edacs capable scanner.

 

[Jay911]

Rick Parrish (Unitrunker) said this in one of the admin forums as we were discussing iDEN scanner futures, and I think (but I'm not sure) that the same applies for other TDMA-employing protocols:

The problem(s) there are most consumer grade receivers are 15 khz bandwidth on the final IF - which is about 10 khz too narrow for 16QAM. The other problem is that a discriminator tap won't work - you need (I think) a proper I+Q baseband signal.

Once you get past that, the real fun starts!

The classic discriminator tap won't cut it for this application. Seriously, you're more likely to see ProVoice than iDEN.

 

[mikewazowski]

I'm still trying to decide if it counts as a 'trunk'.. the fact that it carries multiple audio paths on a single frequency may mean it does.

To me, trunking is using multiple frequencies with some sort of control over where conversations end up.

What we've got here is just multiplexing multiple signals onto a single frequency.

Similar to using ctcss/dcs/nac/P25 talkgroups on a conventional channel.

 

[mikewazowski]

I can see a TDMA scanner in the near future. TDMA is Open Protocol, why not incorporate it in a scanner? Just 5 years ago they said we would never see a Edacs capable scanner.

TDMA certainly is not open protocol. There are many manufacturers variations on TDMA and each is proprietary.

However, TRBO is based on an ETSI standard so it's possible we might see something released.

Just 5 years ago they said we would never see a Edacs capable scanner.

Who was saying that?

It's been 8 years since the BC780 was released and it does EDACS.

 

[DaveH]

Who was saying that?

It's been 8 years since the BC780 was released and it does EDACS.

Not only that; the BC245, the first EDACS scanner, is going on 10-11 years
old, and I believe the PRO-2052 also pre-dates the BC780.

Dave

 

[richster]

Not only that; the BC245, the first EDACS scanner, is going on 10-11 years
old, and I believe the PRO-2052 also pre-dates the BC780.

Dave

Yup 10 years at least. I bought my 245xlt in the summer of '98. Amazingly I still have that thing, and works just like the day I bought it. Except 95% of the digits wore off the keys

It would be great to see the new generation of Uniden digital scanners capable of decoding TRBO.

Regards,
Richster.

 

[SCPD]

Not only that; the BC245, the first EDACS scanner, is going on 10-11 years
old, and I believe the PRO-2052 also pre-dates the BC780.

Dave

Has it been that long, how time flys, your correct, but!!! only months before the first Edacs scanner was released according to this site when it was called something else. eEven Strongsignals.com said it was impossibe and will never happen, Wrong!!!

 

[n1das]

EDACS is supposedly a proprietary format. EDACS scanning supposedly came into being after someone (legally) reverse-engineered the trunking format.

My first EDACS-capable scanner was a RadioShack Pro-92 handheld.