Digital voice on GMRS

[mmckenna]

No matter how you want to debate the issue, you are still not going to get the FCC to start with digital modes on GMRS.
No way, no how, not going to happen any time soon whatsoever. That was just discussed last year, and soundly rejected.

I concur. FCC moves at a snails pace when it comes to stuff like this.
But all it takes is someone filing the right requests and they'll consider it. Might shoot it down again, or they might adopt it.

Hey, how about convincing them into making CB into a FM digital service?
That I could possibly see happening well before GMRS

Simply migrating CB to FM would have a lot of benefits. Many other countries already allow it, so it's not a stretch for the manufacturers.
Cleaner audio would be nice.
Being able to run coded squelch would make it a very usable radio service.
Just think how much better those constant "Auuuuuuuuuuudddddddddiiiiiiiiiooooooooo" calls would sound in FM!

 

[NC1]

I concur. FCC moves at a snails pace when it comes to stuff like this.
But all it takes is someone filing the right requests and they'll consider it. Might shoot it down again, or they might adopt it.



Simply migrating CB to FM would have a lot of benefits. Many other countries already allow it, so it's not a stretch for the manufacturers.
Cleaner audio would be nice.
Being able to run coded squelch would make it a very usable radio service.
Just think how much better those constant "Auuuuuuuuuuudddddddddiiiiiiiiiooooooooo" calls would sound in FM!

And with narrow banding, squeezing in 80 channels would be easy.

 

[SQP]

And let's have digital REPEATERS on CB too!!!!! GEEEEEEEEEEEEZZZZZZZZZZZZZ

 

[prcguy]

We had high power FM repeaters on CB around here. That didn't work out so well, especially for its owner.

And let's have digital REPEATERS on CB too!!!!! GEEEEEEEEEEEEZZZZZZZZZZZZZ

 

[jonwienke]

And if somebody wants to use different modes, they can either get their ham license, or apply for a pair of business frequencies.
Why drag an entire radio service and it's users along with it into something that is unneeded? I only see a handful of people advocating for a change, the other hundreds of thousands are fine as it is.

Another ridiculous non sequitur.

Allowing people do do something doesn't drag anyone into anything. If I'm allowed to use digital to talk to my friends on FRS/GMRS, that doesn't force you or anyone else to do anything, or buy anything you don't want to. Claiming otherwise is bullcrap.

And who made you the ultimate arbiter of what other people need? If digital was allowed on GMRS, I absolutely would use it, for all the reasons I cited previously. A single-frequency DMR repeater on GMRS would be simpler and more economical to set up than analog, wouldn't have channel overlap issues with FRS, would only encumber one frequency instead of two, and would allow simplex as a seamless fallback if the repeater failed or was out of range without the users having to touch a single knob or button on their radios.

 

[prcguy]

Only one person can talk on a repeater at any given time. If someone puts up a legal digital GMRS repeater in the same area on the same frequency, its no different than someone putting up another analog repeater. Each user has to take a turn on that same frequency.

 

[jonwienke]

Yes. But an analog repeater ties up 2 frequencies, not one.

 

[prcguy]

A digital repeater would obviously do the same. My point is it doesn't matter if someone puts up a new digital repeater it shouldn't cause any more problems than putting up another analog repeater on the same frequency.

Yes. But an analog repeater ties up 2 frequencies, not one.

 

[NC1]

Yes. But an analog repeater ties up 2 frequencies, not one.

Most repeaters sit idle 95+% of the time, so having 2 frequencies will accomplish what? So only a couple repeaters in a few congested areas can benefit from a total revamp of GMRS? That's a very tiny slice of licensed users. I still say let's try to get the FCC to do it on the CB frequencies, make it FM, expand it to 80 channels, and maybe drive up the power limit to 50 watts. If any service needs to be updated, it's that one.

 

[SQP]

Yes. But an analog repeater ties up 2 frequencies, not one.

You mean like....ALL REPEATERS?!?!?!?!?!?!?!?!?!?!?!?!?!?!?!?!?!?!?

 

[RFI-EMI-GUY]

No matter how you want to debate the issue, you are still not going to get the FCC to start with digital modes on GMRS.
No way, no how, not going to happen any time soon whatsoever. That was just discussed last year, and soundly rejected.

Hey, how about convincing them into transforming CB into a FM digital service? Now THAT needs updating!
That I could possibly see happening well before GMRS

THANKS! Actually; I was about to suggest that. The UK has analog FM 27 MHz CB. Why not the US? Why not FHSS in CB band? Turn 40 channels into 4000 Talk Groups? It would be a trivial engineering challenge.

GMRS with wideband 16K0F3E equipment is just fine it works well and sounds good there is no reason to wreck the fidelity with another crappy vocoder.

Pro's and cons of the arguments:

1) Narrowband GMRS for "more channels"? NOPE: They are already taken with low power FRS narrow band.

2) Improved range with digital? Slightly, but audio fidelity goes out the window. (Unless you have a Midland radio, and its already gone)

3) Two DMR Timeslots? Is anyone using the capacity of the GMRS channels out there? I doubt it?

4) Easier networking with DMR IPSC? Agreed, but folks are doing this with analog just fine.

5) Encryption? Its not gonna happen. Get a part 90 license for your APX radios.

Suggestion:

Why not focus on developing a 900 MHz FHSS ISM protocol that envelops all the digital advantages of DMR and includes single frequency repeater capability and IP back haul? Why should Motorola have the only product (DTR) in 900 MHz ISM with limited system capabilities?

Folks have already demonstrated that 900 MHz DTR radios can talk as far as GMRS portables.

Instead of messing up GMRS regulatory structure, push to develop a 900 MHz alternative that works within the current Part 15 regulatory framework.

I can assure you that the FCC would rather for GMRS fade away and the /\/\anufacturers will make every effort to make it a cloud service you will have to pay to play.

By the way, The UK and Japan experimented with an analog FM 900 MHz CB band back in the 90's and it worked just fine. Despite it being outlawed, folks are still using it.

 

[RFI-EMI-GUY]

I think if you were to set up a P25, DMR or other digital GMRS repeater with some good hand held radios and show it to a bunch of current GMRS users, they would say "I gotta have that!". And most if not all would switch over as soon as the repeater was legal and available.

P25 is actually very ancient, expensive and flawed technology. DMR is big step above. But those vocoders are trash. Be honest, wouldn't you rather hear "wide band" FM than an IMBE or AMBE vocoder? Even 12 kbps CVSD sounds better. The digital LMR technology was sold on a FALSE premise that it would sound terrific. It does not. It was also pushed into the marketplace by degrading the analog FM channels through narrowbanding under another flawed premise, that there would be a shortage of LMR channels. Once everyone got forced to use narrow-band FM a cellphone or P25 worked better.

 

[DeoVindice]

P25 is actually very ancient, expensive and flawed technology. DMR is big step above. But those vocoders are trash. Be honest, wouldn't you rather hear "wide band" FM than an IMBE or AMBE vocoder? Even 12 kbps CVSD sounds better. The digital LMR technology was sold on a FALSE premise that it would sound terrific. It does not. It was also pushed into the marketplace by degrading the analog FM channels through narrowbanding under another flawed premise, that there would be a shortage of LMR channels. Once everyone got forced to use narrow-band FM a cellphone or P25 worked better.

WFM does sound better than both. Truthfully, NFM often does too. Every mode is a compromise with its own advantages and disadvantages, which is why I'm in favor of making digital available on GMRS in addition to rather than in place of WFM. Personally, I've had had fewer intelligibility issues with newer P25 Phase 1 radios than MOTOTRBO. I'm chalking that up to audio setting issues and believe I partially remedied the MOTORBO situation by selecting a different audio profile. It's quite easy to have an inaccurate impression of digital LMR due to misconfiguration - I found that out when testing some P25 hardware on my own system.

Cell phones are another issue entirely. They fall on their face once there's the slightest amount of background noise and lack the requisite reliability for rural industrial use. The various cell carriers (and AT&T in particular) have spotty and inconsistent coverage in my region; I'll use LMR over one whenever practical.

 

[12dbsinad]

Don't you dare mess with my wideband GMRS! It's the last thing around that actually sounds GOOD!

Implementing digital would come with some problems. The first is the loss of interop with existing GMRS and FRS radio's. Anything that isn't analog voice would be interference to analog users. By GMRS standards all certified radio's must be able to interoperate. You would loose the "listen before talk" and self policing. By the FCC's own words:

"with the use of the interstitial channels by GMRS and FRS units, we do not feel that the gains achieved by implementing narrowband digital techniques outweigh the losses in equipment investments and complications of introducing a new modulation scheme for GMRS radios." That means they want those 40 year old GE repeaters to continue on, as people do invest time and money into them.

That is why it's not allowed. If you want to play, get your hammy ticket... and that's really the end of the discussion, or at least should be.

 

[prcguy]

Are you forgetting the FCC has already issued experimental licenses for digital modes on GMRS? There are people legally using digital on GMRS as we type our comments here. Its happening and the FCC will be looking at the impact of those experimental licenses for future negotiations on the subject.

THANKS! Actually; I was about to suggest that. The UK has analog FM 27 MHz CB. Why not the US? Why not FHSS in CB band? Turn 40 channels into 4000 Talk Groups? It would be a trivial engineering challenge.

GMRS with wideband 16K0F3E equipment is just fine it works well and sounds good there is no reason to wreck the fidelity with another crappy vocoder.

Pro's and cons of the arguments:

1) Narrowband GMRS for "more channels"? NOPE: They are already taken with low power FRS narrow band.

2) Improved range with digital? Slightly, but audio fidelity goes out the window. (Unless you have a Midland radio, and its already gone)

3) Two DMR Timeslots? Is anyone using the capacity of the GMRS channels out there? I doubt it?

4) Easier networking with DMR IPSC? Agreed, but folks are doing this with analog just fine.

5) Encryption? Its not gonna happen. Get a part 90 license for your APX radios.

Suggestion:

Why not focus on developing a 900 MHz FHSS ISM protocol that envelops all the digital advantages of DMR and includes single frequency repeater capability and IP back haul? Why should Motorola have the only product (DTR) in 900 MHz ISM with limited system capabilities?

Folks have already demonstrated that 900 MHz DTR radios can talk as far as GMRS portables.

Instead of messing up GMRS regulatory structure, push to develop a 900 MHz alternative that works within the current Part 15 regulatory framework.

I can assure you that the FCC would rather for GMRS fade away and the /\/\anufacturers will make every effort to make it a cloud service you will have to pay to play.

By the way, The UK and Japan experimented with an analog FM 900 MHz CB band back in the 90's and it worked just fine. Despite it being outlawed, folks are still using it.

 

[RFI-EMI-GUY]

Are you forgetting the FCC has already issued experimental licenses for digital modes on GMRS? There are people legally using digital on GMRS as we type our comments here. Its happening and the FCC will be looking at the impact of those experimental licenses for future negotiations on the subject.

I am not forgetting that it has happened in the past. However I am not finding any such licenses on the ULS system past or present. Can you show me a few??

The process would be an NPRM where the topic gets hashed out with reply comments. You have to beware the FCC, sometimes you get exactly what you asked for and not what you want.

 

[RFI-EMI-GUY]

Way off topic, but a lot of folks went out and bought shiny new SUV's and trucks with 4 and 6 cylinder Turbo GDI (Gasoline Direct Injection) engines to replace those "antique" normally aspirated V8 and V6 engines that were good for 250K miles. Now Hyundai's are failing by the droves burning oil until the pistons and bearings give out. The Fords are now starting to have troubles. New tech is not always best.

 

[12dbsinad]

New tech is not always best.

Name me one technology that the word "digital" means poorer audio quality (by a lot) then it's predecessor. I'll go ahead and wait...

 

[RFI-EMI-GUY]

Name me one technology that the word "digital" means poorer audio quality (by a lot) then it's predecessor. I'll go ahead and wait...

So simple:

Virtually any technology using a lossy VOCODER (Speech CODEC) to reduce voice bandwidth for transmission.

Cellphones
APCO 25 (IMBE/AMBE
DMR (AMBE)
CVSD
FreeDV
etc

Then there is the music world where some audio compression schemes are inferior.

I have attached an NIST study where various digital codecs are being considered for public safety LTE. The baseline is 12,5 KHz Analog FM. You will see that a very high data rate is required to exceed even 12.5 KHz NBFM. You can be sure that actual data rates will be variable "best effort" in practice.

I tried to attach an earlier report by NIST * comparing 25 KHz analog FM with P25 under various conditions the fire service is exposed to . Many Fire Departments chose not to utilize P25 because of audio quality issues.

There have been some efforts to improve, but I can safely say that P25 digital is NOT better than analog FM when considering audio quality.

* Tr-08-453IntelligibilityOfSelectedRadioSystems.pdf

A lot of money has been spent by industry to improve the vocoders and NIST has done lots of studies. If digital were inherently better than analog FM in LMR nobody would have raised such a fuss and had NIST intervene.

On the other hand I bought a CD music player in the 80's and got rid of my turntable. But that was different, the transmission media was several inches in the digital domain and several feet in the analog.

 

[prcguy]

And you forfeited audio quality when you gave up the vinyl for CDs. I think you should be a huge fan of digital radio formats. Analog FM's ten or more KHz of transmission media vs just a few KHz for digital, DMR, Fusion, D-Star, P25, etc.

On the other hand I bought a CD music player in the 80's and got rid of my turntable. But that was different, the transmission media was several inches in the digital domain and several feet in the analog.