DMR Tier 1 Vs Tier 2

[JASII]

I have been reading some things online about DMR Tier 1 Vs Tier 2. I also know that there are smartphones, like the UleFone Armor 3WT, that have a UHF transceiver in them that appears to by DMR Tier 1.

What can you do with a Tier 1 device, since amateur radio is Tier 2? Can a Tier 1 device communicate on simplex with a Tier 2 device? Could a Tier 1 device be used to access an amateur radio hotspot? How will a Tier 1 device behave if an amateur radio repeater frequency, color code and talkgroup were programmed into it? Since there is no provision to select Time Slot 1 or 2, will it simply hear nothing? What if both time slots were active?

 

[Golay]

A Tier 1 device will be heard on both time slots.
I don't believe it matters what the time slot (you may not be able to program a time slot in a Tier 1 radio) and color code is, it would still come across both time slots. I could be wrong of course.

 

[KG7PBS]

No Tier 1 is FDMA. Tier 2 is TDMA.
So basically one uses the entire frequency. It’s still transmit data and data slots. But only one conversation at a time on tier 1.
where as tier 2 is TDMA Time division multiple access The radios talk with each other and sync. So you can use timeslot one and time slot to have simultaneous conversations on one frequency. So look at it this way tier 1 is Simplex. tier 2 is simplex but two people can talk at the same time

 

[datawhisperer]

Is sound quality and different between tier1 or 2 by tier1 using the entire frequency and have the full bandwidth?

 

[slicerwizard]

Highly unlikely. Can't see it being anything but AMBE+2 with the same FEC.

 

[chief21]

There is a lot of confusion regarding DMR Tier 1 and Tier 2. Technically, DMR Tier 1 (under the ETSI specification) was designed solely for the DMR-based digital PMR446 devices sold in Europe and some other countries. PMR446 devices are low power, short-range radios similar to the FRS radios marketed in the US. Since European PMR446 devices utilize 446 MHz frequencies, they can not be used as unlicensed devices in those countries (including the US) where 446 MHz falls within the amateur radio allocations.

The Baofeng models and other so-called DMR Tier 1 radios have actually tested as TDMA, but with digital signals that populate the entire 12.5 kHz channel... likely an oversight by Chinese engineers, as these radios were originally marketed as DMR-compatible. Since these radios have been shown to interfere with normal DMR communications (which utilizes two discrete timeslots in a single 12.5 kHz channel), they have been banned from many amateur DMR systems.

In addition to the digital PMR446 devices that utilize DMR TDMA specifications, there are other flavors of PMR446 in Europe. Some radios utilize analog modulation in a single 12.5 kHz channel (known as PMR446), and some others utilize digital FDMA in two 6.25 kHz channels (known as dPMR). As noted above, none of these radios can be used for unlicensed use in the US.

For those that are interested, there is a Wikipedia article that goes into further detail on this subject.