DMR use with public safety.

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tbmoran48
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DMR use with public safety.

#1 Post by tbmoran48 » 25 Nov 2018 10:32

DMR is not a viable alternative to P25 in public safety. It is contrary to all the established protocols for public safety interoperability. This is a case of an agency not being informed and a salesman willing to just make a sale and money.

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garys
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Re: DMR public safety

#2 Post by garys » 25 Nov 2018 10:37

It's quite viable, just not for interoperability. Kenwood makes radios that can operate on multi modes. FM analog, P25, DMR, pick two. In the Stow area, I'd expect that DMR and FM analog would suffice.

There are other dual mode radios out there as well, so using DMR on a conventional radio system is quite viable as long as the system can still use analog channels for interop.

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ScanBoston
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Re: DMR public safety

#3 Post by ScanBoston » 25 Nov 2018 11:02

I think its a bad idea as well both for interop and if grants come along that you might be able to use as you now have a system that is incompatible with that equipment. I'd think a slower convert to P25 which is what most other communities are doing would be a better long-term solution.

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Re: DMR public safety

#4 Post by jbella » 25 Nov 2018 16:42

Sounds like someone sold them a bag of cucumbers instead of a balanced meal.

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Re: DMR public safety

#5 Post by tbmoran48 » 25 Nov 2018 21:00

It's not viable. The idea is to keep it simple. It was a bad idea and a bad choice.

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garys
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Re: DMR public safety

#6 Post by garys » 26 Nov 2018 14:35

You're entitled to your opinion.
tbmoran48 wrote:
25 Nov 2018 21:00
It's not viable. The idea is to keep it simple. It was a bad idea and a bad choice.

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Re: DMR public safety

#7 Post by tbmoran48 » 27 Nov 2018 07:39

Thank you Gary. That's all fine and dandy that there are radios out there that do multi-mode, but that doesn't help the outside agencies or surrounding communities that don't have the multi-mode radios. Since when does it become the responsibility of other agencies to adhere
to a non-standard format so they can communicate with the oddball town.
Where have you been for the last 18 years? It's all about INTEROPERABILITY!!!
Oh, and by the way Stow does not appear to have modified their license for DMR.

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W1KNE
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Re: DMR use with public safety.

#8 Post by W1KNE » 28 Nov 2018 10:03

Stow is the third town in the Commonwealth to use DMR for public safety comms.

Ludlow Police and Holyoke Fire both went DMR in the last 2 years.

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Re: DMR use with public safety.

#9 Post by cdgordon » 28 Nov 2018 14:25

How about those municipalities that went to P25 while the surrounding towns were still analog?
How about those who run encryption full time?
How about those who's neighbors are on different bands?

Some municipalities can't afford the cost of the P25 radios. Some need more talkpaths than the one per conventional channel that P25 gives. Interoperability doesn't mean that one system has to talk directly with another, merely the ability to set up common communications. DMR consoles can be patched to other systems. Regional networks, simplex analog, etc. An agency that relies on outside agencies regularly and cannot communicate with them is creating a problem. One who rarely calls, perhaps only a couple times a year, doesn't need to worry about spending extra money or changing their own needs for those few incidents that require communicating with the neighbors.

chris

jbella
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Re: DMR use with public safety.

#10 Post by jbella » 28 Nov 2018 20:17

Read the NIOSH report on the Lancaster Mass fire. Then we'll talk about interoperability.

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Re: DMR use with public safety.

#11 Post by cmpsa » 28 Nov 2018 20:18

I'll chime on what I know as a two-way radio tech.

1) analog comms are plain & simple (another agency with a radio on freq and/or scanner can listen).

2) digital comms are awesome, receive & transmit quality is much better than analog, but it's more it.
a) I personally love digital radios, but I'm forced to use DMR if I want radio capacity (i.e. rental radios - install 1 VHF rptr, have 2 rptr talk paths). Second I like ADP/DES encryption for privacy, but it's for P25 digital radios, not for use in DMR radios. So yep, I agree manufacturers design their products to force users to use radios that are ridiculously overpriced by Mr. Scrooge to begin with.

3) It's the same above reason above why Motorola dealerships would sell the CDM mobile series (which CDM is commercial mobile series) and it's in the business/industrial business line of radios, not public safety. The actual public safety radios were so overpriced, dealers hardly sell any, they would sell the CDM/HT series radios. 6 months later a fire dept damages a portable radio at the fire scene, and I wonder why Motorola says "sorry we don't fix physical damage radios", buy another overpriced radio from us..

4) We operate a fleet of DMR digital radios because the digital is so much better for radio coverage, and DMR rptr has 2 rptr talk paths (like having 2 rptrs installed).

5) DMR & P25 digital repeater talk out coverage is greater than the analog coverage.

6) I agree with previous post comments - it's the salesman & radio shops that sell a town DMR digital. An example, it makes absolutely no sense to have a town FD & PD on VHF analog, but sell the town DPW/Hwy Dept DMR radios and put them on DMR digital. You are isolating that single user off from the rest of the others. The FD & PD would have to also have DMR digital radios in order for the whole town to be "100% interoperable" with one another.

7) It is my understanding in the case of of City of Holyoke, they bought Kenwood mobile & portable, the NX-5000 series (which the radios are analog, DMR & P25 capable). I have some of those radios and we can talk on analog, toggle up a channel, talk on DMR, but I have to switch to a different bank/zone to talk on P25. You can mix & match analog & digital, but not DMR digital & P25 digital in the same bank/zone. So DPW/Hwy, FD or PD are interoperable with one another, as they all have the same compatible radios.

8) If P25 digital conventional was TDMA digital, then I'd totally pick P25. Remember DMR digital is TDMA protocol, and P25 (conventional) digital is FDMA protocol. Only 800/900MHz trunked digital can be FDMA/TDMA {i.e. Motorola Type II trunking}.

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Re: DMR use with public safety.

#12 Post by JFR » 29 Nov 2018 08:02

cmpsa wrote:
28 Nov 2018 20:18
FD & PD on VHF analog, but sell the town DPW/Hwy Dept DMR radios
Or PD on P25 UHF, FD on analog UHF, and DPW/MUNI/EMA on DMR VHF like my town.... :mad:

To the OP's point, there is nothing wrong with DMR for public safety as a protocol in of itself. In fact, I find the DMR protocol superior to P25 (2-slot spectral efficiency, no need for a 12.5 kHz FDMA control channel, newer CODEC with better codebook, etc) However, interop capability and subscriber unit durability are not up to public safety needs.

-JR

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ScanBoston
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Re: DMR use with public safety.

#13 Post by ScanBoston » 29 Nov 2018 09:07

I have both JFR and there is no way you can tell me that DMR recovered audio sounds better than P25? P25 is way better both in errors and voice recognition. There's also no comparison with a mid tier radio like an XPR vs APX or XTL. And I have never seen a CDM (bottom tier) in PS vehicle but again perhaps I live to close to the big city. Back to the grant money... There is hardly a city or town in this great commonwealth who hasn't at one time or another gotten a few radios or something for their radio system. They will never get a dime for a DMR radio or DMR infrastructure. All grant money will always be for a P25 or P25 capable.

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Re: DMR use with public safety.

#14 Post by tbmoran48 » 29 Nov 2018 09:27

I'm not debating the technical pros and cons of P25 vs DMR. I'm talking about the real world use of these formats.
Yes, when communities are migrating to P25 it leaves the surrounding communities out. When encryption is used or
communities are on different bands it creates a problem. When going to P25 it's an evolutionary move, eventually
other communities will upgrade and have the ability to communicate. This is not isolating the agency with a non
standard public safety format. The issue is being addressed by establishing national standards for interoperability.
When you ignore these standards you become part of the problem.

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Re: DMR use with public safety.

#15 Post by tbmoran48 » 29 Nov 2018 10:08

jbella wrote:
28 Nov 2018 20:17
Read the NIOSH report on the Lancaster Mass fire. Then we'll talk about interoperability.
That being said, what was the issue or lessons learned from this fatal fire?

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Re: DMR use with public safety.

#16 Post by ecps92 » 29 Nov 2018 11:43

Can you provide the URL ??
jbella wrote:
28 Nov 2018 20:17
Read the NIOSH report on the Lancaster Mass fire. Then we'll talk about interoperability.


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Re: DMR use with public safety.

#18 Post by jbella » 29 Nov 2018 20:46

tbmoran48 wrote:
29 Nov 2018 10:08
jbella wrote:
28 Nov 2018 20:17
Read the NIOSH report on the Lancaster Mass fire. Then we'll talk about interoperability.
That being said, what was the issue or lessons learned from this fatal fire?

One of the issues was the lack of communications between abutting towns that constantly ran to the same calls together. It's all well and good to talk about gateways, patching and all kinds of gee-whiz gadgets, but at the end of the day, or more precisely at the beginning of an incident when things go circling the drain it's not always feasible or timely to have to set up patches or gateways. Direct unit to unit communications is the only reliable, sure fire method. And by using an "alternative" voice mode, you are potentially putting people in harms way, or taking them out of the loop.

I'll be blunt and say as a line firefighter that it is insular, dangerous, stupid and disrespectful of your employees, to put them on an alternate system. If you have the capability (money) to have radios that have various voice modes available to them, you have the capability to adhere to the digital standard that was created to BE the standard. Or just stick with analog.

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Re: DMR use with public safety.

#19 Post by tbmoran48 » 30 Nov 2018 21:24

jbella wrote:
29 Nov 2018 20:46
tbmoran48 wrote:
29 Nov 2018 10:08
jbella wrote:
28 Nov 2018 20:17
Read the NIOSH report on the Lancaster Mass fire. Then we'll talk about interoperability.
That being said, what was the issue or lessons learned from this fatal fire?

One of the issues was the lack of communications between abutting towns that constantly ran to the same calls together. It's all well and good to talk about gateways, patching and all kinds of gee-whiz gadgets, but at the end of the day, or more precisely at the beginning of an incident when things go circling the drain it's not always feasible or timely to have to set up patches or gateways. Direct unit to unit communications is the only reliable, sure fire method. And by using an "alternative" voice mode, you are potentially putting people in harms way, or taking them out of the loop.

I'll be blunt and say as a line firefighter that it is insular, dangerous, stupid and disrespectful of your employees, to put them on an alternate system. If you have the capability (money) to have radios that have various voice modes available to them, you have the capability to adhere to the digital standard that was created to BE the standard. Or just stick with analog.
You have just validated what I've said. No one should arrive on a scene and have to establish patches, gateways or other types of solutions, I'm not advocating that. It is necessary to have an established protocol in place to support the incident. I read the NIOSH report but did not get a sense that radio communications played a part in the death of the firefighter. I can see that there was an overall lack of coordination at the beginning and during the duration of the incident.

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garys
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Re: DMR use with public safety.

#20 Post by garys » 30 Nov 2018 21:47

I was talking with a suburban fire chief today. He said that there is going to be more use of the various fire district interop channels and far less of departments using each others channels on mutual aid calls.

I mentioned the Stow PD system and he pointed out that police generally make far less use of interop than fire departments do. Just about every fire department depends on each other on a daily basis for mutual aid. Most of it is NOT for fires, but for EMS calls. The police generally don't have that sort of issue and are also generally better staffed than the fire department in their town.

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Re: DMR use with public safety.

#21 Post by tbmoran48 » 01 Dec 2018 15:01

garys wrote:
30 Nov 2018 21:47
I was talking with a suburban fire chief today. He said that there is going to be more use of the various fire district interop channels and far less of departments using each others channels on mutual aid calls.

I mentioned the Stow PD system and he pointed out that police generally make far less use of interop than fire departments do. Just about every fire department depends on each other on a daily basis for mutual aid. Most of it is NOT for fires, but for EMS calls. The police generally don't have that sort of issue and are also generally better staffed than the fire department in their town.
The way the fire service operates it is vitally necessary for interoperability. In the past fire
departments made their own plans for communications with their surrounding communities.
Today the fire service has established protocols and radio networks for use by departments in
their fire district, such as Metro Fire, fire district 13. All the assets are available, if command
knows how to use the system. The biggest impediment to it's efficient use has been the lack of knowledge by fire chiefs as to how to use the communications systems.
Don't minimize the police usage of mutual aid channels, they use it more for the exchange of
information between agencies, and for fast moving incidents. Staffing has no relationship to
police use of the system.

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Re: DMR use with public safety.

#22 Post by n1zyy » 03 Dec 2018 10:55

garys wrote:
30 Nov 2018 21:47
I mentioned the Stow PD system and he pointed out that police generally make far less use of interop than fire departments do. Just about every fire department depends on each other on a daily basis for mutual aid. Most of it is NOT for fires, but for EMS calls. The police generally don't have that sort of issue and are also generally better staffed than the fire department in their town.
I was thinking about this the other day in relation to this thread. I routinely hear local FDs signing on with another town when they come in for coverage. Perhaps it happens, but I can't recall the last time I heard a police officer come up on a neighboring town's frequency. For multi-agency incidents, they'll usually end up on BAPERN/NEMLEC (I always forget which of those networks subsumed the other).

Here in Lowell, our PD runs P25, but few (if any) of our neighbors do. I suspect many of the departments may have P25-capable radios, though.

None of this is to say that I think using DMR when none of your neighbors are is a good idea, though.

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Re: DMR use with public safety.

#23 Post by jbella » 03 Dec 2018 20:21

garys wrote:
30 Nov 2018 21:47
I was talking with a suburban fire chief today. He said that there is going to be more use of the various fire district interop channels and far less of departments using each others channels on mutual aid calls.

I mentioned the Stow PD system and he pointed out that police generally make far less use of interop than fire departments do. Just about every fire department depends on each other on a daily basis for mutual aid. Most of it is NOT for fires, but for EMS calls. The police generally don't have that sort of issue and are also generally better staffed than the fire department in their town.

Here are 2 points about the above;

Massachusetts is still very much about local control. If a particular or singular fire chief (or police chief) wants to use his or her channel and not regional ones, it's his or her option. That's the way it is. And it does still happen, no matter what the regional boards, statewide mouthpieces or highly funded metro areas say.

Any city or town is a potential target for a major incident. It's been seen over and over across the country. Isolating yourself because your town or city generally doesn't use interop and you can save your town council $19 is a good way to enhance a disaster.

And for that matter, if your neighbors are all DMR and you go P25, that's just as bad.

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