DMR vs P25

[nd5y]

I think his confusion may come from some of the Kenwood and NXDN Forum documents.

A couple times recently I saw people online state that DMR TDMA has one time slot 6.25 kHz below the RF carrier and the other time slot 6.25 kHz above the RF carrier. I don't remember if that was here or some of the ham radio forums.

They probably learned that from an expert on YouTube.

 

[a727469]

This is what I was referring to. I have seen NXDN advertised before as 2 talkpaths, FDMA. Never seen it done. Wouldn't want to do it, separation is a good thing.

Amused at the "dislike" emoji's and so forth. Nothing I stated was wrong. Just because it isn't done often, and for good reason, doesn't mean it isn't what it says. TDMA & FDMA abbreviations are worth exploring. I don't know it all, and I don't act like I do. But I made my point, for what it's worth. Regardless, when you stop breathing, is when you stop learning. I enjoy these "debates" as everybody can learn something from it. I don't care one bit if I am called stupid or something. But don't just assume there is merely a keyboard rambo trying to show off what they think they know. Some statements are made to entice a response, that may otherwise not get a lot of attention if asked in conventional manner. This was the case.

Y'all try to stay warm, and be safe, got some interesting weather headed in. 🫡

some people just like to use “dislike”…I have never understood or used it since either you are a positive “like” or say nothing. Each to his own! Or at least they should explain the dislike. I had a few of these in another forum and post and asked the individuals why so I could learn something but never got the courtesy of a reply.
Fortunately my life does not depend on ratings from others so I just ignore, although do use the “like” to show my appreciation for others.
In this post I have learned much about the technical aspects of dmr versus P25, and very much appreciate those who have taken the time to explain, but we definitely need to drop the “I know it all” attitudes even if some do know all.😉😀. I am waiting for the “dislikes”❗️👎🙂

 

[Cameron314]

A couple times recently I saw people online state that DMR TDMA has one time slot 6.25 kHz below the RF carrier and the other time slot 6.25 kHz above the RF carrier. I don't remember if that was here or some of the ham radio forums.

They probably learned that from an expert on YouTube.

You would think the name "time slot" would be a hint.

 

[Micformike401]

Or Harris or Icom or BK or….

Wrong Icom offers a radio that does P25 and DMR.. Also Several radios offer both DMR Tier 3 and P25 Phase 2 capabilities. Tait Communications offers the TB9400 base station/repeater and the TP9900 portable radio, while Kenwood offers the VM-5730, VM5830, and VM5930 mobile radios. These devices are designed for mission-critical communications and support both DMR Tier 3 and P25 Phase 2 standards.
Here's a more detailed look at the options:
Tait:
TB9400 Base Station/Repeater:
This device is designed for smooth migration between Analog, P25 Phase 1, P25 Phase 2, DMR Tier 2, and DMR Tier 3.
TP9900 Portable Radio:
This radio is a multiband, multiprotocol portable radio that supports P25 and DMR, including both Tier 2 and Tier 3. It also features enhanced ergonomics and controls.
Kenwood:
VM-5730 VHF, VM5830 UHF, and VM5930 700/800MHz Mobile Radios: These Kenwood mobile radios are designed for digital operation and offer support for analog simplex, analog conventional repeater, analog LTR trunking, digital simplex, digital conventional repeater, digital NEXEDGE networking, P25 Phase I and Phase II, and DMR.

 

[UAT_978]

Wrong Icom offers a radio that does P25 and DMR.. Also Several radios offer both DMR Tier 3 and P25 Phase 2 capabilities. Tait Communications offers the TB9400 base station/repeater and the TP9900 portable radio, while Kenwood offers the VM-5730, VM5830, and VM5930 mobile radios. These devices are designed for mission-critical communications and support both DMR Tier 3 and P25 Phase 2 standards.
Here's a more detailed look at the options:
Tait:
TB9400 Base Station/Repeater:
This device is designed for smooth migration between Analog, P25 Phase 1, P25 Phase 2, DMR Tier 2, and DMR Tier 3.
TP9900 Portable Radio:
This radio is a multiband, multiprotocol portable radio that supports P25 and DMR, including both Tier 2 and Tier 3. It also features enhanced ergonomics and controls.
Kenwood:
VM-5730 VHF, VM5830 UHF, and VM5930 700/800MHz Mobile Radios: These Kenwood mobile radios are designed for digital operation and offer support for analog simplex, analog conventional repeater, analog LTR trunking, digital simplex, digital conventional repeater, digital NEXEDGE networking, P25 Phase I and Phase II, and DMR.

Icom has zero radios that does DMR. They are all in on Idas (NXDN).

 

[KevinC]

Icom has zero radios that does DMR. They are all in on Idas (NXDN).

So I was correct in my statement of...

Or Harris or Icom or BK

 

[mmckenna]

Wrong Icom offers a radio that does P25 and DMR.. Also Several radios offer both DMR Tier 3 and P25 Phase 2 capabilities.

I think you are mistaken. A link to such a radio would prove us wrong.

Kenwood:
VM-5730 VHF, VM5830 UHF, and VM5930 700/800MHz Mobile Radios: These Kenwood mobile radios are designed for digital operation and offer support for analog simplex, analog conventional repeater, analog LTR trunking, digital simplex, digital conventional repeater, digital NEXEDGE networking, P25 Phase I and Phase II, and DMR.

The VM-5x30 do not support NXDN/NexEdge. The only VM/VP series that do are the 8000's.

If you want single band with NexEdge, you need the Kenwood NX version of those radios. NX-5x00 will support analog, plus any two of the digital modes at a given time.

 

[cavmedic]

Icom has zero radios that does DMR. They are all in on Idas (NXDN).

While not DMR, they do offer DPMR radios.

 

[DeoVindice]

Kenwood:
VM-5730 VHF, VM5830 UHF, and VM5930 700/800MHz Mobile Radios: These Kenwood mobile radios are designed for digital operation and offer support for analog simplex, analog conventional repeater, analog LTR trunking, digital simplex, digital conventional repeater, digital NEXEDGE networking, P25 Phase I and Phase II, and DMR.

I wish the VM5000 line supported multiple waveforms. They are P25-only at this time and I have not heard any indications that that will change.

 

[GlobalNorth]

Why?
Because APCO pushed for P-25 and Mother M pushed MotoTRBO for business.
NXDN because Icom and Kenwood wanted their own system.
EDACS because it was obscure and GE said obscurity infers security.
OpenSky because a once-good idea can be destroyed by bureaucratic intransigence and overthinking.

 

[cavmedic]

Why?
Because APCO pushed for P-25 and Mother M pushed MotoTRBO for business.
NXDN because Icom and Kenwood wanted their own system.
EDACS because it was obscure and GE said obscurity infers security.
OpenSky because a once-good idea can be destroyed by bureaucratic intransigence and overthinking.

You spelled BrokenSky wrong.....

 

[kayn1n32008]

Why?
Because APCO pushed for P-25 and Mother M pushed MotoTRBO for business.

Lol. Motorola is Motorola.

NXDN because Icom and Kenwood wanted their own system.

NXDN was a digital format to meet narrowbanding and future proof. It is also the only true 6.25kHz format, DMR is not true 6.25kHz. Not because they 'wanted their own'

EDACS because it was obscure and GE said obscurity infers security.

LMFAO.

EDACS, Motorola Type 2 and Multinet were different formats that were in response to APCO16 compliant offerings. GE offered Provoice, Motorola offered CAI. CAI eventually was adopted by APCO.

OpenSky because a once-good idea can be destroyed by bureaucratic intransigence and overthinking.

Opensky was good for what it was designed for. Data. Not a PS one to many voice system.

 

[Project25_MASTR]

Why?
Because APCO pushed for P-25 and Mother M pushed MotoTRBO for business.
NXDN because Icom and Kenwood wanted their own system.
EDACS because it was obscure and GE said obscurity infers security.
OpenSky because a once-good idea can be destroyed by bureaucratic intransigence and overthinking.

Actually, NXDN fit a specification that was requested in Japan…and Icom and Kenwood are both based in Japan. Why TETRA? Because that fit a spec in Europe.

 

[natedawg1604]

I would just add that much of this discussion is historical. A vast amount of public safety agencies in the US, large and small, have already adopted large P-25 trunked systems. If you live in a jurisdiction with many surrounding agencies already using P25, you would have a very strong incentive to join the system. When many agencies are on the same system, interoperability is very easy to achieve, as adjacent agencies can easily share each others talkgroups as well as program mutual aid/interop talkgroups. As others have noted, there is also ISSI capability between multiple P25 systems.

In many areas of the Country, it is very common for Fire & Police Departments to have talkgroups programmed for all nearby jurisdictions with an adjacent geographic response area (i.e. common Highways, interstates, County Roads etc.). Furthermore, if you're jurisdiction is already within an area covered by a state or regional P-25 system, you just have to acquire subscriber radios to start using the system (granted that is not cheap, but it's a very attractive option).

Yes, it is possible to build links or patches between a DMR and P-25 system, but if you decide to build a DMR system and many of the agencies nearby you are using P-25, you're choosing to isolate yourself to a great extent.

 

[UAT_978]

While not DMR, they do offer DPMR radios.

Which is a close cousin to NXDN.

 

[IC-R20]

Which is a close cousin to NXDN.

Does it have the 12.5khz 9600 mode with better audio quality that NXDN does though?

 

[mmckenna]

Does it have the 12.5khz 9600 mode with better audio quality that NXDN does though?

Nope.

dPMR was always intended to be a very narrow bandwidth mode to make the most efficient use of the spectrum.

12.5KHz NXDN was there to give better audio quality and more data throughput.

 

[kayn1n32008]

Furthermore, if you're jurisdiction is already within an area covered by a state or regional P-25 system, you just have to acquire subscriber radios to start using the system (granted that is not cheap, but it's a very attractive option).

Majority of all Public Safety in my province have left their legacy systems and moved to our province wide L3/Harris P25 Phase 1 system. One of our major cities decided to keep their city owned system and over the years, upgraded it from a mixed mode 3600baud mixed mode system to 9600baud P25 phase 1. They are interconnected via ISSI. There are still some legacy systems in use. Analogue, DMR Tier 2. There is one agency that uses a VHF Connect Plus system, in parallel with our provincial system.

I'm not aware of any agency that is not planning to have at least the capability to at least have some radios on the system to be able to interoperate with other agencies.

Yes, it is possible to build links or patches between a DMR and P-25 system, but if you decide to build a DMR system and many of the agencies nearby you are using P-25, you're choosing to isolate yourself to a great extent.

Sure you can, BUT its a pain in the ass, and if its double vocoded, there is audio degradation, especially with noisy analogue signals being vocoded.

 

[kayn1n32008]

If so, how would you even program that on KPG111 or D1N?

You enter your transmit and receive frequencies, select NXDN as your transmit and receive mode, then select "Very Narrow" in the bandwidth drop down, select your transmit and receive RAN's. bam, you just programmed a conventional NXDN channel. now there is a bunch of stuff you need to set up in other menu's, but that's a bit out of scope here.

 

[RRR]

You enter your transmit and receive frequencies, select NXDN as your transmit and receive mode, then select "Very Narrow" in the bandwidth drop down, select your transmit and receive RAN's. bam, you just programmed a conventional NXDN channel. now there is a bunch of stuff you need to set up in other menu's, but that's a bit out of scope here.

I am referring to splitting the frequency into 2, 12.5 split with two 6.25 + 6.25 adjacent "channels"