Could Uniden Ever Design A Scanner To Properly Decode Trunked Simulcast Systems?

[br0adband]

Oh, and this hypothetical Windows person is not you, bb. But, think back to when you first used a new OS. How proficient were you on it?

Ever seen or heard of the TV show "The Pretender"?

That's me, basically, because I can fit into most any situation like I was born to it, seriously.

And remember, many yarns ago when "personal computers" were far from it but getting there, documentation was plentiful: huge reams of documentation were included with the software and the hardware to get people started. I remember having like 4 lbs of documentation in the IBM PC packaging, literally a ream and a half of paper in the box to go through. Same with most Microsoft products in the 80s and early 90s, even Windows 95 had a rather thick user manual to get people started.

Now, mind you most folks don't actually read documentation like I do or have done, and these days hardly any big companies provide actual paper documentation anymore - it's all digital now with PDF files or something of a similar nature and that just adds to the fact that people don't want to read it. I find it funny that people will stare at and read web pages of various sorts constantly at their computers but tell them to read some actual documentation for hardware or software in a digital format on a screen and all bets are off.

But since we've gone off-topic yet once again, I'll offer my own answer to the question the OP posed in the topic of this thread:

Yes, Uniden can, and they already have apparently based on some available information but it might require some hardware revisions to "get it right" once and for all.

 

[Citywide173]

Discussing the required technology that is currently missing from scanners and what it would cost to add it and what IP barriers are or are not in place is on point. Simple as that. Why does divulging this information get you and Voyager so on edge?

It doesn't get me on edge, it was a specific question asked about a specific manufacturer. The initial statement indicated that it was possible, but would the consumer be willing to spend what Uniden would charge for it? Then people jump in giving the impression that it would only be a $20 price increase because that's what it cost people who are doing it with Dongles and a PC, paying no attention to the fact that a computer is also involved but not factored into the $20 cost because everyone has one. I felt that it was giving a false answer to the initial question. It's nothing against DV Dongles, the associated software or any other component of doing it in an experimental application, just wanting to ensure that the OP or anyone else with the same question wasn't led to believe that it would be an insignificant price increase if Uniden were to implement the simulcast fix.

 

[br0adband]

"If only Uniden would do <whatever>..." is the wish of wishes I suppose, and they're well aware of it. I'm sure there are people at Uniden and Whistler and wherever else that create and design their hardware thinking "It would be cool if we weren't so damned constrained by patent and IP issues and could just make a scanner that I myself would consider pretty awesome..." but of course for those very reasons - the patent and IP crap - they can't and more than likely never will.

Hell, I'm still somewhat pissed that one of my favorite scanners of all time - the BC246T - didn't have MilAir support. I mean really, how tough would it have been to design it with that range opened up? Would it really have caused a price increase or was there a really good reason for not doing it? It could have been something as simple as "Hey, let's gimp the 246T with no MilAir coverage and instead allow the 396T (released at pretty much the same time as Uniden's first Dynamic Memory scanners) to have wide open 25 to 512 MHz coverage so we can charge consumers more for a feature that would actually be rather trivial to enable in the 246T to begin with..."

I know nobody else cares, but for the longest time I did, and in many respects I still do hence me dredging that up for this post.

I don't know the reason and I don't suspect I'll ever find out but even so, sometimes I really despise manufacturers for gimping on features that wouldn't increase the cost of a product yet enable such a feature for additional expense even so.

Anyone remember the original iPhone and the lack of Bluetooth support for file transfers and audio/music listening (no stereo audio? Blasphemy!) even in spite of the Broadcom wireless chip in the device being fully capable of it - and then Apple charging people to enable it with a later firmware update? I remember that pretty well even in spite of me never actually purchasing an original iPhone.

Regarding the pricing thing: I never got anything from this thread that implied a $20 price increase just to add proper simulcast reception to Uniden's scanners, if anything I figured it would have probably been much cheaper overall based on some things that Max pointed out. A trivial thing really, it's just a matter of them actually implementing what's already possible I'd say. If they charged more for it that would be because they'd have to do a hardware revision to bring it into existence because it can't be done with a simple firmware upgrade which means new scanners entirely and of course I can't imagine anyone would cough up another ~$500 just to add proper simulcast reception support.

Compare that figure to the $20 one, if needed. Hell, for $500 these days I could put together a pretty spiffy desktop with a great piece of SDR hardware like SDRplay and make even more things possible including proper simulcast reception with OP25.

 

[slicerwizard]

the "cheap USB TV tuners" are just receivers, plain and simple

No, they're not. Their firmware does most of the heavy lifting involved in DVB-TV decoding. We just use them as dumb receivers / IQ sources.

Because your $20 solution is vaporware without the hardware to run it. The cost of the hardware must be taken into account for an answer that is not a half-truth.

The hardware in the $20 dongles is overspec for the LSM decoding task. So much for hardware costs.

All we want is an admission that PCs are not free and are required to run one of the $20 dongles. (at least that's all I want - I suspect Ed may accept the same)

Now, why do you keep denying that is the case? It's not as if Uniden could add a port for a $20 dongle for a $20 solution.

Wow. Three strawmen all in a row there.

I agree that the basic hardware may be all that is required in the front end, and that cost is trivial (I said exactly that in post 46). What is not known is that the current processor in the scanner would be able to handle the processing involved. Would it require a higher cost processor? Additional circuitry?

There are a LOT of semi-modern computers that will not run an SDR plus DSD+ well. I would be willing to bet those have more processing power than the x36 scanner.

Therefore, saying $20 in parts will fix the Uniden scanners lacks credibility. It has nothing to do with the electric bill or the internet service. It has everything to do with the cost to make that $20 in parts WORK.

And yet again you refuse to acknowledge that a $20 dongle already has far more processing power than LSM demodulation requires.

It's nothing against DV Dongles, the associated software or any other component of doing it in an experimental application, just wanting to ensure that the OP or anyone else with the same question wasn't led to believe that it would be an insignificant price increase if Uniden were to implement the simulcast fix.

I'd say your goal has been accomplished.

 

[UPMan]

he, a professional electronics engineer and scanner hardware designer

To clarify, my degree is in business with major emphasis on macro economics (money and banking) and business and intellectual property law. However, I have a strong background in software (systems analysis) and enough engineering knowledge to only occasionally make a fool of myself when talking to an engineer. I rely on actual hardware/rf engineers to design hardware and primarily design the UI/UX (which is implemented by actual software engineers).

 

[mtindor]

I wish I knew why this thread was specifically made to mention Uniden. The discussion applies to ANY scanner manufacturer, or any electronics manufacturer whatsoever. ANY company that does already provider scanner that handle C4FM, and ANY company that could design one in fhe future COULD also provide support for CQPSK.

Yeah, I know, this got shoved into the Uniden tavern [likely because it's Uniden in the subject], but this is an issue that any scanner manufacturer should be working on.

Mike

 

[jcardani]

Did anyone read my post #26?

CML microcircuits have a demodulation chip (CMX981) that already performs the Pi4/DQPSK heavy lifting without the need for a computer. Feed the radio's 450 or 455 KHz IF to a simple I/Q demodulator as input to this chip and you have the hardware. The existing radio's uC would need to interface to the chip for control.

The price of this chip is around $13.50 in quantity 100.

 

[Voyager]

So much for hardware costs..

How much longer are you going to argue a point that was conceded many posts ago?

And yet again you refuse to acknowledge that a $20 dongle already has far more processing power than LSM demodulation requires.

As it relates to DTV, maybe. But we aren't talking about DTV. We are talking about LSM which requires the power of a PC to process.

If that's not true, please tell me where to connect the speaker to the dongles.

And I'm still waiting for the YouTube video of your dongle added to the x36 that shows it decoding perfectly.

 

[Voyager]

I mentioned this a few years ago but I believe an add on solution may be able to be built. I envisioned a small add on modem board that would take the scanner's 450 or 455 KHz IF as input , down convert the signal, separate I & Q, demodulate the LSM CQPSK with a Pi/4 DQPSK demodulator chip, re-modulate it with a C4FM chip to baseband audio, and finally output that signal back to the scanner before the radio's micro controller.

Why would you want to remodulate it? Just demodulate it and feed that to the audio amp input (switched, of course).

CML micro manufacturers chips that can be used for this function. This may even be able to be done with a very fast micro controller since the code used for OP25 is open source. I'm sure a talented electrical engineer would be able to design such a device.

OP25 may be claimed open source, but does it violate the DVSI IP?

 

[slicerwizard]

We are talking about LSM which requires the power of a PC to process.

Aha! That explains why I saw a fireman with a laptop hanging off his XTS5000 yesterday! Damn, had me confused there, but now I understand.

Meanwhile, back in the real world, LSM actually requires less processing power than C4FM, thanks to its built in symbol synchronization signal.

 

[cpetraglia]

Did anyone read my post #26?

CML microcircuits have a demodulation chip (CMX981) that already performs the Pi4/DQPSK heavy lifting without the need for a computer. Feed the radio's 450 or 455 KHz IF to a simple I/Q demodulator as input to this chip and you have the hardware. The existing radio's uC would need to interface to the chip for control.

The price of this chip is around $13.50 in quantity 100.

Here is my simple observation. My 996XT shows a P25 error rate that is right on the money. It directly corresponds to the quality of voice decoding. If the scanner is smart enough to figure that out, why can't it be made smart enough to correct it? Consider haw many of us buy new scanners to attempt to improve our LSM reception. I am on my fourth one. I wont buy the X36 series because of obvious reasons. We all want one scanner to do what it's supposed to do. I would be willing to pay a lot more for it.

Chuck

 

[slicerwizard]

There is a limit to how many errors a receiver can correct. Since scanners use the wrong demodulation method for simulcast transmissions, the error rate gets very high.

I'm sur yuu cna corret ths sentenc, but yu cnt corrrct evrrthg, lekk hhes kaxhh oo ddr ppl?

 

[jcardani]

Why would you want to remodulate it? Just demodulate it and feed that to the audio amp input (switched, of course).




OP25 may be claimed open source, but does it violate the DVSI IP?

Because the CML chip does not output baseband analog audio. The demodulation/re-modulation method was for my idea of an add on board for existing scanners. Of course the scanner manufacturers could use the CML Pi/4 DQPSK chip only but the output is digital and would need to output directly to the DSP.


Why would DVSI's IP be violated demodulating Pi/4 DQPSK? Their patents cover the IMBE and AMBE vocoder.

 

[Voyager]

Aha! That explains why I saw a fireman with a laptop hanging off his XTS5000 yesterday! Damn, had me confused there, but now I understand.

We are talking about DONGLES. So if he was using a DONGLE to decode P25, then he would have had a PC hanging off his belt.

You may understand but that means you are being intentionally antagonistic. (which explains a lot).

Either that, or more likely you are getting frustrated by trying to defend a losing argument. Actually, that is more likely.

 

[slicerwizard]

No, you want to pursue some dongle-related strawman. You can't debate the technical aspects, so you chase after shadows.

LSM is easier to decode than C4FM. Doesn't require enhanced processing power. End of story. Deal with it.

 

[Voyager]

And you say we are on edge....

BTW, where can I get some of those $20 XTS5000s?

 

[slicerwizard]

Obvious troll is obvious.

 

[KA1RBI]

We are talking about LSM which requires the power of a PC to process.
<snip>

That statement is quite simply false - Both FSK4 and LSM do require a processor (DSP or CPU) of some kind. The processor _need not_ be that of a PC. The fact that the agency radios can decode LSM properly standalone (i.e., without a PC) is sufficient to put the lie to that statement. The agency radios contain sufficient processing power in the form of CPU and DSP chips to do the job they were designed for.

scanners use the wrong demodulation method for simulcast transmissions <snip>

This is the fundamental truth that Voyager (and others) are so freaked out about, and that UPMan (and others) can never admit....

Obvious troll is obvious.

Quite obvious. Facts are irrelevant to the troll, perhaps because the facts require a technical understanding that is beyond their capacity. It's pointless to try to talk about fundamental laws like the Nyquist rate and the constraints that dictate the proper sampling rates and how LSM requires top rates literally hundreds of times less than the maximum sample rate of the RTL, as an example. Another possibility is that these trolls just misconstrue everything deliberately ...

73

Max

 

[UPMan]

SPS = Symbols per Second. It is not the sample rate. It is the rate at which symbols (i.e. changes in voltage, frequency, or phase changes) occur. In the case of the signals we are talking about, each symbol represents one of 4 possible states (i.e. 2 bits). So, the bit rate of the data stream = SPS * 2.

SPS is the correct terminology when referring to the signal's data throughput, but S <> samples.

 

[JASII]

Could Uniden Ever Design A Scanner To Properly Decode Trunked Simulcast Systems?

After reading about the Unication G4, I will probably get one of those as my next radio. I am most interested in monitoring the Minnesota ARMER system. It is quite difficult for consumer grade scanners to properly decode the signals.

http://forums.radioreference.com/al...ew-g4-g5-pagers-somewhat-limited-scanner.html

http://communications.support/threa...lkgroup-scan-a-P25-system?highlight=Unication

Hoffman Radio Network - 717-275-4783

Unication USA