New Repeater Channels for GMRS in 2024

[gortex2]

@Sshannon your going to need to explain this one. Maybe I misunderstood what your saying. 

 

For any digital radio and encryption all the encryption is done at the subscriber end (portable/mobile). Nothing is done on the repeater in either DMR or P25. This doesn't matter if its trunking or conventional. A true digital repeater will repeat any encryption key. Some will have an interface to decode encrypted audio but many do not. Example is the Quantar can be hooked up to a DIU with encryption module to get 4 wire audio to a remote or console. With a GTR its done via IP via console. 

 

[Sshannon]

25 minutes ago, gortex2 said:

@Sshannon your going to need to explain this one. Maybe I misunderstood what your saying. 

 

For any digital radio and encryption all the encryption is done at the subscriber end (portable/mobile). Nothing is done on the repeater in either DMR or P25. This doesn't matter if its trunking or conventional. A true digital repeater will repeat any encryption key. Some will have an interface to decode encrypted audio but many do not. Example is the Quantar can be hooked up to a DIU with encryption module to get 4 wire audio to a remote or console. With a GTR its done via IP via console. 

 

I might be misunderstanding. Is the entire data packet (including the Brandmeister ID) encrypted, or just the digital output of the audio codec?  For example, the Brandmeister network requires a Brandmeister (BM) ID or it will ignore a transmission (I assume). If that BM ID is encrypted, the Brandmeister network wouldn’t be able to recognize it. 
Same for the talk group. 
 

So if that’s the case, (and maybe it’s not; maybe only the digitized audio is encrypted) then encryption would break the network connections, I would think. 
 

[Sshannon]

2 hours ago, Sshannon said:

I might be misunderstanding. Is the entire data packet (including the Brandmeister ID) encrypted, or just the digital output of the audio codec?  For example, the Brandmeister network requires a Brandmeister (BM) ID or it will ignore a transmission (I assume). If that BM ID is encrypted, the Brandmeister network wouldn’t be able to recognize it. 
Same for the talk group. 
 

So if that’s the case, (and maybe it’s not; maybe only the digitized audio is encrypted) then encryption would break the network connections, I would think. 
 

So, looking at the protocol specification:

https://www.etsi.org/deliver/etsi_ts/102300_102399/10236101/02.04.01_60/ts_10236101v020401p.pdf
 

it only makes sense that the payload is the only portion of the communication that’s encrypted. That means I’m very probably wrong in thinking that encryption would affect repeaters. 

[gortex2]

OK. So I've never dealt with Encryption with HAM stuff but at least in P25 they block the bit for encryption and it will not talk to a hotspot if tied to brandmeister. I don't know how the DMR version works. I know a friend of mine built his own "server" for our hot spots and we were able to pass encryption over the hotspots so it wasn't a hotspot issue. This was P25 and not DMR as none of my DMR stuff at the time did encryption. Since then I've picked up some XPR's but have had no interest to use hotspots anymore. With the advent of LTE and other features of a P25 core I can do all we were doing with hotspots with commercial gear now. 

There was a big discussion on another communication forum about this. 

 

[intermod]

On 11/22/2023 at 1:03 PM, gortex2 said:

There is no solution. Its not part of the service. There are other services to use if you want to use digital. The service has been around for decades. Many of us have had repeaters for decades for our personal use. I don't know why the huge influx to the service happened but its good and bad. Very few places in the US have issues with congestion so I don't see changing a service because one city or state has an issue.  

Is this problem limited to one city or state?  Or maybe neither of us really know.  Are you suggesting a "one size fits all approach" is the only way? 

The FCC has created a list of "major metro areas" in Part 90 where different rules apply.  Why not apply this same concept to GMRS?

It is highly unlikely that additional radio channels will be allocated for GMRS in specific regions.  So it seems logical that the best approach is to make better use of what we already have.  Digital provides 4X the capacity within the same spectrum.  It is not clear if this will actually increase perceived interference or reduce it since far fewer repeaters would be needed to support the same number of users.   

For example:  I have two separate user groups operating simultaneously on a single DMR repeater today, as it provides for two simultaneous channels (slot 1 and slot 2).  If I were to lose the DMR license for this and have to go back to legacy analog operation, I now need to build a second repeater and use yet another GMRS channel for that second repeater.  I suspect this might increase interference to those on the new channel......

[Sshannon]

22 minutes ago, intermod said:

The FCC has created a list of "major metro areas" in Part 90 where different rules apply.  Why not apply this same concept to GMRS?

Because GMRS is for common folks to buy off the Walmart shelf and use fairly informally.  Part 90 radios and location specific rules make sense when commercial radio shops are in charge of configuration and sales.

[intermod]

1 minute ago, Sshannon said:

Because GMRS is for common folks to buy off the Walmart shelf and use fairly informally.  Part 90 radios and location specific rules make sense when commercial radio shops are in charge of configuration and sales.

But we have had two classes of users for almost 30 years - the "common folk" or bubblepack users (all direct-mode/simplex) and the more professional users that operate repeaters.    100% of our DMR users figured out their radios within about 1 day when first getting on.    

[wrci350]

17 minutes ago, intermod said:

100% of our DMR users figured out their radios within about 1 day when first getting on.    

You must be new here.  50% of the new posters in these forums cannot even figure out how to program an analog repeater into their new GMRS radio.  Do you seriously think that DMR will work for "every man"?
And before you ask, I am *very* familiar with programming a DMR repeater and DMR radios, both Motorola and other brands.  It's orders of magnitude more difficult than programming an offset and a tone or two for an analog repeater.

[Radioguy7268]

You also have the issue that while DMR is a basic digital standard, every manufacturer has their own flavors that they have built on top of the standard to add features for their user base. So when one repeater owner decides to add Restricted Access for Security, and then another one wants to add enhanced Privacy/encryption, another will decide to implement GPS Location. Good luck trying to them all on board with your DMR dream.

As already mentioned before - go get yourself an FB6 Private Carrier license on Part 90 if you want to do DMR. If you're determined that it needs to be done on GMRS frequencies - then go write up a petition for rule change & wait around for 5 or 10 years to see if the FCC responds.

 

 

[intermod]

18 hours ago, wrci350 said:

You must be new here.  50% of the new posters in these forums cannot even figure out how to program an analog repeater into their new GMRS radio.  Do you seriously think that DMR will work for "every man"?
And before you ask, I am *very* familiar with programming a DMR repeater and DMR radios, both Motorola and other brands.  It's orders of magnitude more difficult than programming an offset and a tone or two for an analog repeater.

Apparently you did not understand my post.   I once had reading comprehension challenges but was able to overcome them early in my childhood.  I can contact you offline and make some recommendations if you wish. 

Should we dumb down consumer products for the lowest common denominator, or give consumers a choice??

Did you not agree that there (at least) two classes of users on GMRS?

Are you thinking that Amazon, Walmart and others would only offer DMR radios?  Why would that be? 

[intermod]

13 hours ago, Radioguy7268 said:

You also have the issue that while DMR is a basic digital standard, every manufacturer has their own flavors that they have built on top of the standard to add features for their user base. So when one repeater owner decides to add Restricted Access for Security, and then another one wants to add enhanced Privacy/encryption, another will decide to implement GPS Location. Good luck trying to them all on board with your DMR dream.

As already mentioned before - go get yourself an FB6 Private Carrier license on Part 90 if you want to do DMR. If you're determined that it needs to be done on GMRS frequencies - then go write up a petition for rule change & wait around for 5 or 10 years to see if the FCC responds.

It will add a number of choices to the service, and to some it would cause complexity.   But its complexity a consumer chooses to take on or not.  Buy analog if you like that - and you could likely save some money as well.   I never mentioned encryption, GPS, etc. as there is no reason that the current restriction on these would need to change.  RAS can be accomplished today through various schemes in analog as well, so this is not specific to DMR. 

FB2/4/6 remain an option as you said before. 

Gortex2 said "Very few places in the US have issues with congestion so I don't see changing a service because one city or state has an issue.".  So in reality maybe the FCC pushed us in the right direction by allowing site-specific authorizations for DMR.  A federal rule change is quite an undertaking.       

[intermod]

From experience over the years it seems the FCC's main concern about mixing any type of digital in is it impacts the "listen-before-talk" (LBT) etiquette and the ability to work out interference issues via voice (analog users would not be able to hear the digital users).

Of course, analog users could not hear the digital users' callsigns, but they could hear the repeater callsign that is always transmitted in analog.   

LBT can be solved today by requiring the digital users to operate dual-mode capable radios (ones that will decode digital or analog on the same channel automatically).  Hytera, Anytone and others already have this feature.  Or require Busy Channel Lockout (BCLO) be used on the digital-capable radios.  So the manufacturers of digital-capable radios would be required to build one of both of these features into their products - make it a type-certification issue.

The the other direction - i.e., analog users causing interference to digital users - is not an issue as most all digital radios are capable of receiving analog.  So they could get callsigns and contact analog users that are causing IX.   Or - place a requirement on the digital user that they must accept interference since they are the new kids on the block. 

[BoxCar]

I will chime in and plainly state: MIXING DIGITAL AND ANALOG RADIOS ON THE SAME FREQUENCIES DOES NOT WORK --  PERIOD. We Part 90 coordinators fought through this issue when Moto introduced MotoTURBO. It reached the point where the 4 Public Safety coordinators froze all applications to either convert existing systems to digital or create new digital coordinations. We were finally able to create guidelines that often resulted in converted systems allowed lower radiated power or antennas being aimed lower on the horizon. New coordinations were also restricted on radiated power, often much lower than originally requested.

[intermod]

26 minutes ago, BoxCar said:

I will chime in and plainly state: MIXING DIGITAL AND ANALOG RADIOS ON THE SAME FREQUENCIES DOES NOT WORK --  PERIOD. We Part 90 coordinators fought through this issue when Moto introduced MotoTURBO. It reached the point where the 4 Public Safety coordinators froze all applications to either convert existing systems to digital or create new digital coordinations. We were finally able to create guidelines that often resulted in converted systems allowed lower radiated power or antennas being aimed lower on the horizon. New coordinations were also restricted on radiated power, often much lower than originally requested.

I had a few DMR applications delayed back in 2016 for exactly that.   One key reason that DMR was causing more issues was the repeater duty-cycle was higher (part manufacturer default settings, part traffic-related, and use of constant GPS messages).  They had me reduce power in my case, but they were also considering directional antennas in others.

But in the seven years since it seemed to reach an equilibrium and everyone settled in.  The vast majority of systems that are actually in use here on UHF are digital now (maybe 80/20 DMR/NXDN).  So you all-caps comment appears incorrect and a bit out of date.

It works, but Part 90 is also a different environment.  That is why I suggested using BCLO, dual-mode radios as GMRS is a different beast.

But great ideas.  Maybe require new DMR repeaters to run lower power and/or use directional antennas.

G 

[Lscott]

On 11/23/2023 at 11:07 AM, AdmiralCochrane said:

Per varying modes maybe, but DMR seems to be extremely popular on VHF 

Just about all the DMR repeaters by me are on UHF.

[wrci350]

5 hours ago, intermod said:

Apparently you did not understand my post.   I once had reading comprehension challenges but was able to overcome them early in my childhood.  I can contact you offline and make some recommendations if you wish. 

Should we dumb down consumer products for the lowest common denominator, or give consumers a choice??

Did you not agree that there (at least) two classes of users on GMRS?

Are you thinking that Amazon, Walmart and others would only offer DMR radios?  Why would that be? 

Oh I understood it perfectly, and I understand this one perfectly too.  But thanks for making nasty comments about me because I don't agree with you.

GMRS is intended to be a "purchase off the shelf" communication service.  Sorry that you don't agree with that either.

Yes, there are those who use GMRS the way FCC intended it to be used, and those who want to make it another UHF amateur radio service without a license test.

I don't think I said anything about what kind of radios would be sold and by whom.  What I said was that the average person who was new to GMRS would have a really hard time programming a DMR radio.

I'm really happy for you that "your users" didn't have any trouble programming a DMR radio to use your repeater.  How many users do you have?  10?  50?  1000?  If you think that automatically extends to every GMRS user in the US, you are wrong.

[intermod]

I don't ever start nasty comments; I only reply to them.  But I try to add some constructive comments that might help certin individuals.

Agree that the vast majority of GMRS radio are "purchase off the shelf" (OTS).  But once the FCC permitted repeaters, the radios needed to be a bit more complicated.  Mobile radios were then available, and these are also a bit more complicated overall.   So clearly the FCC did not intend this to be only OTS.  They intended both. 

All I am saying is why handicap users who are willing to put the effort into it?  The off-the-shelf radios will always be available for the majority of users.  

Even digital radios can come in bubble-packs, pre-programmed with all the required digital settings.  Then the user does not even need to care. 

[wrci350]

29 minutes ago, intermod said:

I don't ever start nasty comments; I only reply to them.  But I try to add some constructive comments that might help certin individuals.

All I am saying is why handicap users who are willing to put the effort into it?  The off-the-shelf radios will always be available for the majority of users.  

Even digital radios can come in bubble-packs, pre-programmed with all the required digital settings.  Then the user does not even need to care. 

Oh really?  Did my "You must be new here" comment bother you that much?  (BTW ... I knew you weren't new.  That was a joke.)

All the required digital settings?  Really?  OK I'll bite.  What color code and talkgroup are we going to use on DMR GMRS?  What if I don't like those settings, because there is another repeater a few miles away that is using them?

Here's my opinion.  If someone wants to get into DMR, they need to get their Technician license.  I read every day how easy that is, so shouldn't be a significant barrier.

One of the FCC rules for GMRS is (to paraphrase) "play nicely with others".  A DMR repeater does not play nicely with analog users.

[intermod]

42 minutes ago, wrci350 said:

.... What color code and talkgroup are we going to use on DMR GMRS?  What if I don't like those settings, because there is another repeater a few miles away that is using them?

....One of the FCC rules for GMRS is (to paraphrase) "play nicely with others".  A DMR repeater does not play nicely with analog users.

Oh - you are referring to repeater-capable radios.  Most OTS radio don't have repeater capability because its way too complicated, as you say.  Just allow them to change the color code - done.   There are only 16 to choose from.  The same way an analog radio user would change CTCSS/DCS codes if the same thing happened.   No different. 

Play nice - agree.  That is the general guideline.  What about BCLO and dual-mode would not be a way to play nicely?

Also - I just considered you may be the kind of user that operates carrier-squelch.  Digital signals are more annoying to listen to (but they don't cause more destructive interference than analog).  If so, CTCSS/DCS can take care of that.  We have to run CTSCC/DCS full time in this area so that we don't hear all the commercial bubblepack and digital traffic.   I just create a channel for each repeater I want to listen to (with CTCSSS/DCS) and scan them.

The bubble-pack radios come with CTCSS/DCS enabled so they won't know any annoying signals even exist.  

[gortex2]

12 hours ago, intermod said:

 But once the FCC permitted repeaters, the radios needed to be a bit more complicated. 

Uh....Since my father got his first GMRS license it was repeater. I dont know anyone back in the day that only used simplex. Our first license was 1 repeater license with 6 mobiles. I'd have to dig way back to see when repeaters came to be but it was 40+ years ago. 

Again I go back to there are many services you can use to use digital. Hell get our own part 90 channel and use that if you too lazy to use ham. We did that for SAR stuff for a few years then went back to analog as it worked. And no one could agree on P25 or DMR. I would see that the case with GMRS also. Ham can't even agree on a digital format. 

[Lscott]

4 hours ago, gortex2 said:

Ham can't even agree on a digital format. 

The problem with digital voice modes is there are so many of them. I have radios for D-Star, DMR, NXDN and P25 Phase 1.  Nothing yet for YSF, or dPMR which is mainly an EU license free service like FRS here but digital. Haven’t seen it in North America yet.

If that wasn’t enough there is a new one, M17.

https://m17project.org

 

[Sshannon]

6 hours ago, gortex2 said:

Ham can't even agree on a digital format. 

There’s no need. That’s part of being a ham, getting to try different things. 

[gortex2]

46 minutes ago, Sshannon said:

There’s no need. That’s part of being a ham, getting to try different things. 

Agree but that was my point. Ham can use digital and can't come up with what's best. I don't see manufacturers building Part95 radios that support a digital format if there isn't one defined specifically. 

[AdmiralCochrane]

22 hours ago, intermod said:

clearly the FCC did not intend this to be only OTS. 

I think you are incorrect about this.  Proof is required type acceptance requirement. 

[Adamdaj]

On 11/22/2023 at 10:06 AM, Lscott said:

I've caught some very sporadic DMR traffic on channel 18 by me. It was a few transmissions during the day lasting a few seconds each. I haven't heard it in many months. I suspect either somebody miss programmed a radio, or did so deliberately. In any case it stopped and I suspect the local FCC might have had a hand in ending it.

There was a YouTube Video where 2 individuals were using an FRS channel in DMR format. Of course, I have to admit that sometimes I test DMR Radio using an FRS channel. I forget the manufactures, but there is DMR FRS radio out there.