Digital vs Analog voice

[bill4long]

Ergo, it's use in ham radio has shown it's limitations as an "interoperable" medium where disparate networks collide with dropped packets, lackluster audio, and challenging experiences for new hams. YSF and D-Star are relatively painless in comparison, and YSF in particular has some of the best audio I've heard, rivaling our $6800 APX8000s and $10,000 APX8500s on our $19.1 million dollar Astro 25 LSM trunked radio network. The ease of being able to have an out of box experience where one can literally VFO in a YSF repeater and GOTA with good digital audio, easy to get on wide area systems, and just HAVE FUN without pissing away hours building codeplugs, dealing with buggy CPS and garbage pail firmware from offshore products, or living within the limits of a radio system designed for school buses and mall security hodgepodged for ham radio.

I do DMR, Fusion and DStar. And I agree. But DMR + hotspot is cheap and non-proprietary. A lot of hams like that. And Brandmeister and TGIF networks are quite stable these days. (I know that DStar is not really proprietary, but only Kenwood produces a DStar radio and it's a very pricey hand-held. I don't know anyone who has one. Moreover, DStar is not very attractive to newcomers these days since it uses the older codec.)

 

[mmckenna]

I won't argue whether or not the APX6000/8000 is more rugged than the APX900/XPR7550, but the biggest reason that firefighters carry the APX6000XE/8000XE is because a salesman convinced someone spending taxpayer money to give these to the Fire Personnel.

Exactly. The issue with Motorola is the SALES department. Good radios, vicious marketing. Got tired of sales people telling me what I could and what I couldn't do with our money/taxpayer funds.

It's not an issue if DMR will work. It works just fine. But there's more money to be made in P25, and that's where the sales guys want to push it.

 

[rescue161]

I have several repeaters on one antenna network (one transmit and one receive). I would routinely demonstrate that digital could be readable on the fringe coverage areas of the repeaters when analog was not readable. There were two P25 Quantars at 110 Watts, one DMR at 40 Watts and two analog at 40 Watts. My test would be to compare the DMR against the the other two analog machines, since they were all at 40 Watts. DMR always won. I usually demonstrated this to skeptics and it always opened their eyes when they saw it first hand.

 

[N4KVE]

Terrible audio in what way?

Missing syllables, & very high pitched uncomfortable to listen to audio. When the radio is scanning, just by listening to people talk, I can tell if it’s Rick’s System, or Bob‘s System.

 

[n9upc]

To go back to the OP's original question...

Digital is going to be different than analog...(duh) but the way I look at it is as a solution or means to an issue. Digital, regardless of mode, is going to offer different things based on the mode of choice. Here is just a few of some quick pros/cons:
DMR: Pro - Allows 2 talk paths per repeater / Con - Bastardized by cheap chinese radios
NXDN: Pro - helps with narrowbanding / Con - The fight between Kenwood and Icom on it has not made it fully compatible between the two
P25: Pro - PS standard / Con - Vocoders have made (newer) radios $$$$$$$
D-Star: Pro - 1st designed amateur digital voice / Con - Vocoder starting to get old as dirt
Fusion: Pro - 2nd designed amateur digital voice / Con - Only made by Yaesu

As for the encryption on digital...I feel that a slight range reduction (note SLIGHT) does occur and that is because of the data sync. I even saw this back in the days of analog and DVP for motorola. I have especially seen it on multipath issues as I drive by some huge grain silos in my town. Not surprised at all and this is just the name of the game.

Good luck and have fun learning in your research.

 

[AI7PM]

DMR: Pro - Allows 2 talk paths per repeater / Con - Bastardized by cheap chinese radios

Nails it. I'll add operators with poor mic technique and failure to understand and set levels in their programming.

 

[romanr]

To go back to the OP's original question...

P25: Pro - PS standard / Con - Vocoders have made (newer) radios $$$$$$$

Good luck and have fun learning in your research.

I doubt that the AMBE+ Vocoder really contributes to the cost differential since DMR and P25 use the same vocoder. I don't know the terms of the licensing agreements, but the cost to license the P25 CAI almost certainly eclipses the cost to license the Vocoder.

 

[n9upc]

I doubt that the AMBE+ Vocoder really contributes to the cost differential since DMR and P25 use the same vocoder. I don't know the terms of the licensing agreements, but the cost to license the P25 CAI almost certainly eclipses the cost to license the Vocoder.

I feel that this is a big part based on some of the thing I have seen as pricing.

Example (yes it is Kenwood) but on the NX-5000 series:
P25 List $ 575
DMR List $ 60

 

[romanr]

I feel that this is a big part based on some of the thing I have seen as pricing.

Example (yes it is Kenwood) but on the NX-5000 series:
P25 List $ 575
DMR List $ 60

Both use the same vocoder, so that can't account for much of the total cost, can it?

 

[rescue161]

You can also lock out the Chinese radios from using your repeater if you want.

 

[kayn1n32008]

You can also lock out the Chinese radios from using your repeater if you want.

Encryption, LCP and RAS for the win.

 

[kb9mwr]

I doubt that the AMBE+ Vocoder really contributes to the cost differential since DMR and P25 use the same vocoder. I don't know the terms of the licensing agreements, but the cost to license the P25 CAI almost certainly eclipses the cost to license the Vocoder.

It's possible many of the Chinese DMR radios are using bootleg Indusic AMBE... for that matter Motorola has a number of patents on DMR things.. I suspect most things make in China aren't really following other countries intellectual property laws. And quite honestly why should they if they don't believe in that sort of thing? After all, they own our debt, so they are going to do whatever they want.

 

[bill4long]

It's possible many of the Chinese DMR radios are using bootleg Indusic AMBE..

Hard to say, and it wouldn't surprise me. But at very least, they create AMBE2 compressed code, which make the question moot, IMO. The algorithm is correct, regardless.

 

[GlobalNorth]

But how about the radio itself? Since the APX900 is a P25 first cousin to the XPR7550, do you think a firefighter, or cop would carry an APX900? Maybe a city employee sitting in an office, but not a firefighter. They’ll carry an APX6000/8000 because they‘re 10 times more rugged.

You'd be surprised at what some towns, cities, and counties will issue the troops for public safety use.

I once worked for a department that was, except for a Motorola base station console that was way out of date when I was there, all Midland. We used to call it "plumber band radio". The "radio shop" owner that pasted the mess together was a former Radio Shack manager who couldn't get the franchise he wanted, so he started his own radio business with his formal training consisting of an Army AIT school in radio comm maintenance.

 

[mmckenna]

You'd be surprised at what some towns, cities, and counties will issue the troops for public safety use.

I once worked for a department that was, except for a Motorola base station console that was way out of date when I was there, all Midland. We used to call it "plumber band radio". The "radio shop" owner that pasted the mess together was a former Radio Shack manager who couldn't get the franchise he wanted, so he started his own radio business with his formal training consisting of an Army AIT school in radio comm maintenance.

Midland makes pretty good stuff. A lot of the California Highway Patrol low band base/repeaters are Midland.
But yeah, a bad shop can screw up anything.

 

[N4KVE]

When Florida still had Florida Marine Patrol, now they are FWC, they were on low band. They knew they’d be on a state wide 800 Astro System, but that was still years out. So they needed some radios to replace the GE’s that were dying. They used Midland, & it was good stuff, not to be confused with their cheap FRS radios.

 

[RFI-EMI-GUY]

Yeah, but to be realistic, that is not Motorola in the USA marketing Trbo to public safety. Motorola here in the states would NEVER market it that way. In fact, I specifically had Motorola sales guys tell me that if it was public safety, it HAD to be P25.

But yes, we all know that it works fine for that application. Issue is that Motorola can't charge more for it.

Its Motorola in Taipei saying it is public safety grade. If it is good enough for the rest of the planet why not here?

 

[mmckenna]

Its Motorola in Taipei saying it is public safety grade. If it is good enough for the rest of the planet why not here?

I agree. P25 took for ever to get off the ground. The idea for it to be fully interoperable across all brands has been slow to happen. The plan for it to become so popular that it would be cheap never happened either.

I'd much rather see one of the less expensive digital modes become the default standard. But if you even suggest that to an APCO guy, they'll damn near have a stroke.

 

[RFI-EMI-GUY]

I agree. P25 took for ever to get off the ground. The idea for it to be fully interoperable across all brands has been slow to happen. The plan for it to become so popular that it would be cheap never happened either.

I'd much rather see one of the less expensive digital modes become the default standard. But if you even suggest that to an APCO guy, they'll damn near have a stroke.

I mentioned DMR to some folks at the P25 booth at IWCE 2018. They acted like they never heard of it!

P25 is tremendously expensive and unnecessarily complex. It takes a lot of parts to keep it propped up. To be honest, I have been in this business a long time and the performance of the vocoder embarrasses me. I was once one of those /\/\ evangelists praising the wonders of P25 when it was barely a CAI. I recently brought some 12 Kbps Securenet back to life and the audio quality of the "crude" CVSD is really much better. CVSD does its magic in a simpler way, no trickery.

 

[mmckenna]

I mentioned DMR to some folks at the P25 booth at IWCE 2018. They acted like they never heard of it!

I have a bumper sticker on the inside of one of the bins on my service truck:
"Fire ground radio should go digital when the hydrants go digital!"
Was given it by someone else in the industry. At one point there was a reward for anyone that could get a photo of one stuck on the back of a Motorola Service shop van. Came close a few times, but never did.