The Future of Paging and P25

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motofreak008
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The Future of Paging and P25

Post by motofreak008 »

The company I work for is in the middle of upgrading a county in the area to a P25 simulcast system piggy-backing off of the state system. The customer ordered the Digital Tone Signalling option on the radios for fire and EMS as they were told by the salesperson that it would work, even though none of the service techs had even heard of the option before. I did get to take some time and figured out how to program it in and how it works and color me impressed. All these years of hearing how P25 paging wasn't going to be a thing and Motorola had no interest in developing it.

There were a few quirks trying to get it to act like one would expect and one complaint I have is that instead of a Page channel, the receiver doesn't open until the proper page sequence, you have to have a button programmed to Voice Mute. I'm a firefighter/paramedic so I have plenty of user experience as well and personally I would prefer the channel option over the Voice Mute button. I feel like it's easier to bump a button to turn off the mute than it would be to change the channel and a lot of firefighters and EMTs carry radios that have a page channel in them already, so they're pretty used to changing channels when they get a call.

So far testing seems to work well, we even were able to get a Unication G4 to work but more on that later, granted it's only on the bench and during the day. I'm just looking at starting some dialogue on what the future plans for P25 may be and if there's any word of a /\/\ pager that will be P25 capable? I'm sure you all have heard about it, but there is quite a demand for them. In my department some people prefer to carry just a radio while others would like to keep their radios in their vehicle and just carry a pager and then others don't care and carry both, especially now since we are already on the state system.

Now about that G4. I've gotta say, I'm not impressed. Motorola's software can be confusing at times, but this software is on another level. It just doesn't come across as very friendly and just seems so clutter. It's colorful, no doubt, but at first glance it just seems like too much to take in at once. And then trying to navigate around get it programmed is a chore of its own. It took us awhile to figure out to get it to go off with QCII and not their talkgroup alert. (I mean come on how well did they honestly think that would work and go over with system admins? One talkgroup per dept with the pager going off every time it hears traffic? For a few hundred dollars less I can buy a portable scanner that will alert when there's traffic on a talkgroup.) Once that was figured out after getting the instructions emailed to us by Unication and trying to decipher their help files, the next challenge was the alert tone. O M G. For whatever reason, I couldn't get it to change and the default tone that sounds like a smoke alarm was VERY obnoxious, but the other tech tried something and got them to change. There were many other cons about it, but I don't wanna completely trash them here, unless you wanna hear more and then I'll challenge myself to get it all typed in the time it takes for it to boot up and find the system to scan.

But let's get some dialogue going here, I'm very curious to know if Motorola has plans to get a P25 pager out there and some other thoughts on the topic.
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wavetar
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Re: The Future of Paging and P25

Post by wavetar »

When I was at APCO close to three years ago, the Motorola folks told me they were working on a P25 pager, in response to the Unication product. However, haven't heard a peep about it since! Not sure if they were blowing smoke, or if it just died during the exploratory R&D phase.
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WNCradio
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Re: The Future of Paging and P25

Post by WNCradio »

Can anyone explain how the P25 "tone signaling" option on the APX radios works with legacy QC-II tones? The engineers at DVSI have told me that the AMBE+2 vocoder still only processes a limited number of tones without distortion. Rather, tones within the range 156.25 to 3812.5 Hz are interpretted in 31.25 Hz steps and shifted to a center freq for that tones range. That means that a lot of the standard QC-II tones are not processed by the vocoder without distortion. Some of the QC-II tones fall between the 31.25Hz bands and are subject to random interpretation between the two closest standard interpreted tones. This is all consistent with what I see in the APX 16 CPS help files, where it lists the acceptable tone ranges and also lists a number of unacceptable tones. This list does not line up well at all with the standard QC-II tone freqs. So with "P25 tone signaling" now being touted as an APX option and company tech blurbs saying that it works with well over P25 with legacy QC-II signaling, I'm confused about how that is possible.Anyone have any insight on this?

Also, I would be very interested in details on the programming of paging tones for the APX and how well this working out. As for future Motorola plans for P25 pagers, I believe Unication already makes the Minitor for Motorola. My guess is that any future Motorola P25 pager might be a rebranded G4.
motorola_otaku
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Re: The Future of Paging and P25

Post by motorola_otaku »

I work for an agency that gets a lot of first-out stuff (it helps to not be your average duhhhhhumb customer) and if M is developing a P25 trunking pager our sales reps haven't told us... and they would be *very* eager to sell them to us.

The Unication pager is a nice toy, but without Phase II (any day now!!1!) it's useless for us and virtually useless for anyone else in my market.

One important thing to consider with paging over P25: for sufficient tone fidelity the tones have to be encoded from a networked MCC7000-series console, or transmitted through an APX base or consolette. XTL radios don't "understand" QCII and won't encode the tone audio right. And when transmitting through a base/consolette audio level adjustment is critical or the tones will overmodulate and distort. It's fairly easy to set up with a MCC5500 console, and with a little bit of work it can be done with Zetron or other third-party consoles.

I haven't actually tested a Unication for QCII over P25 (again, no Phase II :( ) but in APX radios it's simple and straightforward: just enter the standard QCII tone freqs. 1x1 and 1x3 tone timing work equally well also. Also, the capcodes are the same as Centracom capcodes, so whatever widget you have for building capcodes from tone freqs will still work.
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motofreak008
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Re: The Future of Paging and P25

Post by motofreak008 »

motorola_otaku wrote:I work for an agency that gets a lot of first-out stuff (it helps to not be your average duhhhhhumb customer) and if M is developing a P25 trunking pager our sales reps haven't told us... and they would be *very* eager to sell them to us.

The Unication pager is a nice toy, but without Phase II (any day now!!1!) it's useless for us and virtually useless for anyone else in my market.

One important thing to consider with paging over P25: for sufficient tone fidelity the tones have to be encoded from a networked MCC7000-series console, or transmitted through an APX base or consolette. XTL radios don't "understand" QCII and won't encode the tone audio right. And when transmitting through a base/consolette audio level adjustment is critical or the tones will overmodulate and distort. It's fairly easy to set up with a MCC5500 console, and with a little bit of work it can be done with Zetron or other third-party consoles.

I haven't actually tested a Unication for QCII over P25 (again, no Phase II :( ) but in APX radios it's simple and straightforward: just enter the standard QCII tone freqs. 1x1 and 1x3 tone timing work equally well also. Also, the capcodes are the same as Centracom capcodes, so whatever widget you have for building capcodes from tone freqs will still work.
+1 on that reply.

The little bit of playing around we did with it in the shop was with an APX900 and APX6000 and it was pretty impressive. We didn't go throw every tone, but it worked well with the ones we tried. I liked how the alert tone was default to the Minitor tones. I've been curious about what it would sound like on an XTL/XTS, if it would be able to decode a QCII, which as has been said already, probably won't work.
Jim202
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Re: The Future of Paging and P25

Post by Jim202 »

Here in southern Louisiana, I frequently hear paging tones being sent over a number of the LWIN talkgroups.

As has already been mentioned, it is important that the page tone level be lower than the normal voice audio, so that it doesn't get distorted any more. Even in analog systems, it is important that the paging tones stay out of compression. Paging tones don't do well if they get distorted. They need to be about 2/3 the level of normal voice audio to stay out of compression and as such not get distorted.

I am double talking myself here, but many radio techs today just don't understand this problem. Keep paging tones out of compression to avoid distortion. When the paging tones get distorted, the paging receivers have a hard time decoding the tones. When the deviation is set correctly, the pager can decode signals just about down into the noise. Many times I have been in an area where i could not understand what the dispatcher was saying because of a weak signal. yet the pager decoded the tones just fine.

Jim
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kb4mdz
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Re: The Future of Paging and P25

Post by kb4mdz »

IMO, poor pager RX & Decode is also a function of software decoding, vs. old style reeds/forks, or even active filters. Think there was some discussion of this a few years ago here on batboard. Makes it more important to keep good control of modulation levels. Jim202, maybe it's time to set up some lab-type experiements comparing different modulation levels of paging tones & decoder types, to demonstrate why keeping tone out of limiting is so important.
motorola_otaku
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Re: The Future of Paging and P25

Post by motorola_otaku »

motofreak008 wrote:I've been curious about what it would sound like on an XTL/XTS, if it would be able to decode a QCII, which as has been said already, probably won't work.
Astro and Astro25 radios produce something akin to a pan flute on decode. On encode it sounds... bad.

The trick is in the APX firmware. On encode they shift sustained tone audio between a high and low frequency to a set frequency, and do the reverse on decode... and reproduce the actual tone locally in the radio. DTMF works the same way. The reproduced tone is sufficiently clean to drive external decoders, like a Genave RXC-3000 or a Knox box. Better still, in APX mobiles flashed for GA09000 you can steer VIP outputs with QCII tone sequences.
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