Unication G5 TRS talkgroup paging via QCII

[APX8000]

I'm trying to confirm whether or not the following is true:

For alerting over P25 trunking, the pager does not actually decode tones sent over a talkgroup. Rather, the pager simply assumes that a particular talkgroup IS the unique paging address. In other words, for each set of QCII tones you might have for the different departments within a County, you would need to create a new talkgroup for each of those departments. So that instead of the pager actually decoding QCII tones over a single talkgroup, it instead assumes that when a particular talkgroup is active, it alerts.

Most of the County Dispatch Centers setup multiple QCII tones on one frequency or ONE TALKGROUP. This is the way is also works currently with the APX Tone Signaling. Instead, the system admin would have to literally create a talkgroup for each paging resource on the console. Then instead of dispatching over a single talkgroup like it's done now, the dispatchers would have to manually select the talkgroup based on who they're toning out? So my County has over 50 fire departments each with its own set of QCII tones. I would have to create 50 new TALKGROUPS, one for each department ????

That's how the FAQ for the G4/G5 appear to read...it makes it seem like you can enter both a QCII combination AND a TGID. So naturally you'd think that it can actually decode those tones on that talkgroup...but if you try to add BOTH of those to the same Channel, it balks because the TGID is duplicated....

 

[mikewazowski]

One talkgroup for each station you want to page out.

There was an earlier thread where Unication confirmed the G4/G5 won't do two tone over P25.

 

[APX8000]

Thanks Mike. I scrolled through the threads but couldn't find an answer. Well that sucks !


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[owenbricker]

If two tone is being used then why not use the conventional frequency the tones are dropped on?.

 

[GTR8000]

If two tone is being used then why not use the conventional frequency the tones are dropped on?.

Just off the top of my head, I can think of two good reasons:

• Trunked systems often have superior coverage vs analog paging resources. Wider area coverage, better in-building penetration, more transmitter sites, etc.
• It's much more efficient to have the device scan a single trunked system vs multiple resources. By scanning the dispatch talkgroup vs the conventional frequency, you can also scan for activity on other talkgroups without missing a tone out.

QCII (two-tone paging) over P25 is nothing new, and contrary to popular misconception, it's absolutely feasible.

I won't get into all of the technical aspects of it, but suffice to say that contrary to another popular misconception, the audio of the tones is not simply compressed to digital format where it sounds awful on the subscriber end. In fact, the tones are inherently part of the IMBE and AMBE+2 vocoder, which the subscriber device recognizes in the bit stream.

Motorola has provided "Tone Signaling" paging over P25 in the APX series since December 2014, and it works flawlessly. The radios are able to discern and decode the full spectrum of QCII tones over a single talkgroup, no different than programming a Minitor pager to decode multiple tones over a single analog conventional frequency.

Oh and it works on P25 conventional, P25 FDMA trunking, and P25 TDMA trunking. In fact, it's more robust over TDMA than FDMA, allowing for a wider array of tones.

It sounds like Unication took the easy way out, and rather than designing the device to properly interact with the DVSI vocoder, they put the burden on the system administrator. So now a system administrator would have to create 20, 30, 50, 100 talkgroups to take the place of each legacy paging resource on the console to support these pagers in P25 trunking mode. And oh yeah, if you want to hear anyone else get toned out, you have to scan all of those new talkgroups. Dispatching multiple agencies to the same incident simultaneously means now having to dispatch them all individually on their personal dispatch talkgroups.

Silly, really. I'm sure there will be quite a few system administrators who will rightfully say "No, thanks...not happening on our system.", and that is a shame. Nobody wins with that scenario.

 

[n3obl]

I got rid of my G4 as they will never alert due to needing around 130 talk groups just on fire side. Initial literature had call page capability in there. That would have been great as I would just put the Id number for the base for station that get alerted.

 

[ZapBugs]

I asked for the same thing. Reply was that the tones are not stable enough to decode.
I can feed them from another P25 scanner to a PC and decode them every time.

Why do I need this? Very simple. The P25 system replaced the analog system. No maintenance is being done to the analog system and it is not receivable on a pager at my house. So if the G5 can alert most of the time, that's better than nothing now. I would even welcome 100% of the time with occasional false alarms.

 

[mikewazowski]

I think that reply was in reference to sending audio tones over P25.

The new method is to regenerate the tones locally so they sound as good as analog.

A local system is doing this with DMR and the tones sounds great.

 

[krokus]

... Then instead of dispatching over a single talkgroup like it's done now, the dispatchers would have to manually select the talkgroup based on who they're toning out? So my County has over 50 fire departments each with its own set of QCII tones. I would have to create 50 new TALKGROUPS, one for each department ????

The dispatch audio can still come over that talkgroup, if wanted. (Which is probably a good idea.)

Michigan is setting up these new talkgroups as pagegroups, which are handled a little differently by the system. Since there will be no affiliated radios, the pagegroups will be "forced" onto the site(s) designated for the coverage area.

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[GTR8000]

The dispatch audio can still come over that talkgroup, if wanted. (Which is probably a good idea.)

Michigan is setting up these new talkgroups as pagegroups, which are handled a little differently by the system. Since there will be no affiliated radios, the pagegroups will be "forced" onto the site(s) designated for the coverage area.

And it's horribly inefficient from a system administration viewpoint, both from the standpoint of having to create dozens of individual talkgroups and console resources, as well as having to assign every talkgroup to the requisite Site Access Profile(s) to ensure they actually broadcast when the consoles are keyed.

Oh yeah and since there's still no firm date for TDMA capability, that means that in order to support these things on full-TDMA systems, the system administrator has to waste valuable channel resources by forcing all of those talkgroups down to FDMA mode.

I would never cater to a single device like that.

If the Motorola APX series can precisely decode up to 91 discrete tone frequencies over a single TDMA talkgroup, so could a properly engineered G4/G5. :roll:

 

[krokus]

If the Motorola APX series can precisely decode up to 91 discrete tone frequencies over a single TDMA talkgroup, so could a properly engineered G4/G5. :roll:

Not if M is using some proprietary crap, like they tend to do.

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[David_Oney]

We are exploring other methods of alerting as well. QCII is not out of the picture it is just not as reliable as it is on Analog so we went a different more reliable route but it's not out of the question. I hope to give our customers many different options for alerting because every circumstance is different.

 

[GTR8000]

Not if M is using some proprietary crap, like they tend to do.

It has nothing to do with "proprietary crap" from Motorola. The tones are an integral part of the DVSI codecs (IMBE and AMBE+2).