Some General DMR Questions

[RFFR]

Hi all,

New user here and I'm hoping this is the right section to discuss some general DMR questions I've come up against.

I've been studying DMR and am aware of the three tiers. The gist I have is Tier 1 is based off of PMR466 in the EU and is analog. Tier II brings digital capability while still being able to be used in analog mode and Tier III is Tier II with trunking. Sound about right?

Some questions that have arisen from this:
1. Because Tier 1 operates in the 446 MHz band, is it illegal to use Tier 1 capable radios in the US? I've read some stories about European tourists causing headaches for hams by stomping all over 446.
2. Since it must be licensed in the US, who would most use Tier I in the US? Is this mostly hams using DMR or is Tier I used elsewhere regularly?
3. I found a channel plan for DMR Tier I, but not for Tier II or III. Does anyone know if these exist? If not, does the FCC just assign a frequency within the band for use with II or III?
4. If there is no channel plan, how could I go about finding licenses that reflect DMR assignments within the FCC database? I am currently looking up assignments within 66-960MHz that have an emdes of 7K60FXE or FXD, but how accurate would that be? I know DMR II and III operate in the 66-960 band, but so do a lot of other things according to the frequency allocation charts...how could I best determine that the license I'm looking at is most likely for DMR and not some other LMR system?

If this is the wrong forum, my apologies. I couldn't find a specific forum where this may be relevant and this seemed like the closest match

Thank you for any advice in advance!

 

[jaspence]

DMR ?

466 is not a ham frequency in the US.

Tier I is more like a FRS radio than ham or commercial and is license free in Europe.

In the US, tier II for hams uses that standard band plan which is not done by channels but by frequency. The commercial use is by assigned frequency also. and can be on other frequencies outside the 400 MHz band. DMR is always digital, but the frequencies can also be used with analog or other digital modes such as D-Star or Fusion..

 

[RFFR]

466 is not a ham frequency in the US.

Tier I is more like a FRS radio than ham or commercial and is license free in Europe.

In the US, tier II for hams uses that standard band plan which is not done by channels but by frequency. The commercial use is by assigned frequency also. and can be on other frequencies outside the 400 MHz band. DMR is always digital, but the frequencies can also be used with analog or other digital modes such as D-Star or Fusion..

I made an error...it should have been 446MHz, not 466MHz.

 

[jaspence]

Still not usable in the US. This might help understand the tier plans. https://en.wikipedia.org/wiki/Digital_mobile_radio

 

[RFFR]

Still not usable in the US. This might help understand the tier plans. https://en.wikipedia.org/wiki/Digital_mobile_radio

I've read the link a few times. In fact, this part of the wiki article is what prompted my Tier I question:

DMR Tier I products are for licence-free use in the European 446 MHz band. In the US, the 446 MHz range is primary US Government with the amateur radio service a heavy secondary user. Some DMR radios that make it across the ocean have caused interference issues with licensed amateur operations.

 

[jaspence]

That should read dPMR. https://en.wikipedia.org/wiki/Digital_private_mobile_radio explains how dPMR works and the very limited band width used. The chart at Updated ARRL Amateur Radio Frequency Charts Now Available shows amateur radio band plans for the US.

 

[nd5y]

1. Because Tier 1 operates in the 446 MHz band, is it illegal to use Tier 1 capable radios in the US? I've read some stories about European tourists causing headaches for hams by stomping all over 446.

446 MHz is allocated to amateur radio in the US. It's not legal to use unless you have an amateur radio license. It doesn't make any difference if it is DMR or FM or any other mode.

2. Since it must be licensed in the US, who would most use Tier I in the US? Is this mostly hams using DMR or is Tier I used elsewhere regularly?

It depends on if there is any Tier I equipment available that works on US land mobile frequencies. I don't think I have seen any. It's not popular here.

3. I found a channel plan for DMR Tier I, but not for Tier II or III. Does anyone know if these exist? If not, does the FCC just assign a frequency within the band for use with II or III?

There is no channel plan for DMR. The FCC doesn't assign certain modes to certain frequencies.
The available frequencies are listed at
https://www.ecfr.gov/cgi-bin/text-idx?&mc=true&node=se47.5.90_120&rgn=div8 for public safety licensees and
https://www.ecfr.gov/cgi-bin/text-idx?&mc=true&node=se47.5.90_135&rgn=div8 for industrial/business licensees.
Frequencies are normally assigned for a particular location with geographical separation between licensees to reduce interference. Licensees must apply for a frequency coordination from a FCC approved frequency coordinator before applying for a license.

4. If there is no channel plan, how could I go about finding licenses that reflect DMR assignments within the FCC database? I am currently looking up assignments within 66-960MHz that have an emdes of 7K60FXE or FXD, but how accurate would that be? I know DMR II and III operate in the 66-960 band, but so do a lot of other things according to the frequency allocation charts...how could I best determine that the license I'm looking at is most likely for DMR and not some other LMR system?

The only way you can tell is by listening. You can see if a particular license has emission designators for DMR, but what is licensed might not be what is used in real life.

I don't think you can search licenses by emission designator on the FCC search pages. Try this web site. Digital Frequency Search

 

[phillmobile]

There are 4 Tiers not 3, Maxxwave in the uk operate the only nationwide Tier 4 system in the country

 

[w8red]

Tier 4 DMR Where?

There are 4 Tiers not 3, Maxxwave in the uk operate the only nationwide Tier 4 system in the country

Um.... DMR is a ETSI standard. Not saying I keep up with it 100% but since when is there is Tier 4?

Their are 3 Tiers
DMR Tier I: is dPMR
DMR Tier II. DMR Tier II covers licensed conventional radio systems
DMR TIER III is the trunking protocol on Top of Tier 2.

What is Tier 4 and where is it in the ETSI specs?

If it isn't' in the ETSI specs then it is NOT DMR by international standards.

Tom