Why the need for two separate systems?

[n1chu]

Anyone got an answer as to why towns choose to put their schools on a DMR system and not just give them their own talk group on the P25 trunking system they use for PD/FD/DPW?

 

[Cheeseburgers]

Good question... I want to add, is there a larger plan to move all municipal LE, Fire etc. to the CLMRN?

 

[Firebuff66]

APX900 with P25 trunking options $1900
XPR3500 DMR portable $325

 

[Mr_Boh]

Bunch of different reasons.

Subscriber/infrastructure cost, grant restrictions, and good old fashioned politics immediately come to mind. A less common answer is features/functionality. Politics is typically the biggest reason, but if you've ever seen what goes into a P25 trunking site vs a networked DMR repeater, it's quickly obvious about why there is a cost gap (in initial deployment + ongoing support).

But to @Cheeseburgers's point, I don't understand why in CT there isn't more of an effort to put municipalities on the state system. I mean each state seems to be handling the statewide radio network concept differently, but it seems like it would be the best option.

Connecticut is one of the places where I see fire trucks with rows of portable subscribers lining the inside of apparatus to be interoperable.

 

[Firebuff66]

There is a huge effort to do just that, The state system only became robust enough to add more users about a year ago and since then they have added almost a dozen new services, so they are well on their way

 

[kayn1n32008]

Bunch of different reasons.

Subscriber/infrastructure cost, grant restrictions, and good old fashioned politics immediately come to mind.

P25 is priced to maximize the separation of tax dollars from the taxpayer. DMR is marketed at ‘business’ who are trying to minimize overhead costs.

A less common answer is features/functionality.

Pretty much DMR can do most everything P26 does... except securely sore AES keys

 

[Mr_Boh]

Pretty much DMR can do most everything P26 does... except securely sore AES keys

And that's the point, right? Not just if it can do something, but how it does something. Public safety agencies throw around a lot more "mission critical" requirements than the schools which is also a tax-funded entity. Seen plenty of public safety agencies demand high availability/redundancy for non-core and seriously under utilized functionality which just helps contribute to system cost. Also I wonder what a coverage test and site engineering for a schools project looks like compared to the public safety system.

 

[N1GTL]

The state system only became robust enough to add more users about a year ago and since then they have added almost a dozen new services, so they are well on their way

Still not nearly enough to offer in-building overage in every school in the state. They have areas where cars will not work.

 

[cg]

In some towns, the schools are like a separate town. Separate personnel departments, purchasing, maintenance, plowing, mowing, etc. It is actually surprising that the schools are using the less expensive system as they do like to spend the taxpayers money and then some.

Portable coverage is a big issue with CLMRN. It was designed for 95% mobile coverage. While there have been and continue to be improvements, it is still tough (read expensive) to get the portable coverage percentage high. Groton, Norwich and Bloomfield all had to add sites for better coverage.

chris

 

[byndhlptom]

Another reason....

Tying into the state system probably requires a monthly/annual cost per radio. Subscriber costs can get very expensive quickly.

Their own system is probably looked at as a one time cost.....

The need to cover just the building and immediate surroundings make the state system seem like major overkill.

budgeting does matter.....



$.02

 

[cg]

No fees to join the state system in Connecticut.
Connecticut is unique in the US for how we do things. 3rd smallest state, 169 cities/towns but we have 315 fire departments and 91 police departments. No county form of government. Highest per capita income in 2010 census.

300+ years of tradition unimpeded by progress

chris

 

[cpfinlay]

Sometimes organizations have restrictions on capital expenditures. Leasing equipment and service (DMR) would be a way around that. I don't know if that's the case for any particular organization... just throwing it out there as another possible reason in addition to those already mentioned.

 

[Mr_Boh]

Not going to solve the world's problems in a RR forum thread, but I think most people wish they could see CLMRN do what some states have done which is if they want to be a primary user and have in building coverage they get the locality to contribute to system build out to make up the different from what the state requirements are and what the locality would need. Even in some of these states, DVRS is a suitable answer to the in-building coverage question. A DVRS costing 10's of thousands of dollars is still cheaper than a radio site and the engineering costs associated with it.

No county form of government.

And thus is the most difficult problem, and why you don't see a lot of P25 in CT, but also see FDs rolling around with racks of various subscribers from different vendors all covering different things.

 

[garys]

Public Safety systems in general have far more stringent requirements than commercial systems. The coverage requirements are much different if you need 95% in building coverage as opposed to 95% coverage for vehicles. Other than private ambulance services in my area, I see almost no portable radio use. The oil delivery guy doesn't need to be able to talk back to dispatch from the basement of a house. OTOH, the police and fire do need that sort of coverage.

The P25 standard was developed by career public safety communications officials to meet the needs of public safety. No doubt, Motorola and all of the other two way radio manufacturers had input, but it was APCO that took the lead. That's why P25 is an open standard (but not open source) commications standard.

If you applied the coverage standards of P25 public safety to DMR, the cost difference wouldn't be that much.

P25 is priced to maximize the separation of tax dollars from the taxpayer. DMR is marketed at ‘business’ who are trying to minimize overhead costs.



Pretty much DMR can do most everything P26 does... except securely sore AES keys

 

[kayn1n32008]

Public Safety systems in general have far more stringent requirements than commercial systems. The coverage requirements are much different if you need 95% in building coverage as opposed to 95% coverage for vehicles. Other than private ambulance services in my area, I see almost no portable radio use. The oil delivery guy doesn't need to be able to talk back to dispatch from the basement of a house. OTOH, the police and fire do need that sort of coverage.

The P25 standard was developed by career public safety communications officials to meet the needs of public safety. No doubt, Motorola and all of the other two way radio manufacturers had input, but it was APCO that took the lead. That's why P25 is an open standard (but not open source) commications standard.

If you applied the coverage standards of P25 public safety to DMR, the cost difference wouldn't be that much.

At the end of that word salad, building a DMR trunk system, that provides 95/95 in building coverage, will still cost a fraction of the exact same coverage from a P25 system. Why is the portable P25 radio on an officers belt worth more than almost the entire rest of his gear? Until Motorola coined their ‘mission critical’ tag line, people were taking Waris portables into IDLH environments for 2 decades with out issue. What changed? Why is an equivalent radio platform now not good enough?

Even today, I can go to a refinery or other petrochemical plant site, and more than likely I will be given a Waris IS rated portable, maybe a Jedi portable, or a XPR6850IS/XPR7550IS. The odd company has P25(one local refinery has APX6000 800MHz subs on a 800MHz phase 2 system).

P25 is all about maximizing separation of tax dollars from taxpayers.
Having said that, is an APX8000XE a tough radio? Yes. Is it worth $5k-$10k optioned out? I’d argue it’s not.

 

[wtp]

they could be a "radio hog"
down here the school administration is on the county radio system, and rarely use it, but...
at a school building they have radios for
maintenance.
calling out the parents coming in to pick up kids.
principal to teacher comms.
special ed. teacher gets their own radio to principal or office for emergencies.
there is almost 20 schools in the county, so multiply that use by 20.
and the buses are on the county system and tie up their channel for some time at the start and end of school.
all of this can bog down a system, or you really have to have quite a bit devoted to just them.

 

[mmckenna]

Keep in mind that a lot of these large regional systems charge a fee per subscriber unit.

For a school that may not need wide area coverage, it can be a real waste of money. If the radios sit unused, it's a waste of money. If it's just for talking across school grounds, no need to put it on a regional system.

And then you have to figure on the traffic engineering that goes into designing the radio system. Adding a lot of new radios will need to be considered when looking at the amount of voice paths you have available on any given site.

And there's really no need for individual schools to talk directly with public safety. Much easier to give school resource officers a campus radio to use. It's often a selling point, "interoperability", but in every case I've ever run across at work, officers do NOT want to be stuck talking directly to a non-public safety users in an emergency. Big difference in communications discipline.

And then, yeah, the cost of radios is a big factor. Teachers don't need to be carrying around an APX level radio to discuss school bus movements.

 

[n1chu]

Good question... I want to add, is there a larger plan to move all municipal LE, Fire etc. to the CLMRN?

I believe the availability is there. If they care to take advantage they may do so. I believe it’s probably a lot cheaper than paying for a new trunked P25 system. Especially if they have to build out a 700 MHz or 800 MHz system from scratch. The added receive sites alone add substantial costs. But there are others who can afford to own their systems outright, and for various reasons, like it that way. But I don’t know, there very well may be a “push” by the state to join and help defray the costs of the statewide system, I’ll let those more knowageble on the subject field that one. I can tell you the Town of Avon planned their own trunked system but ran into difficulties when an antenna site owned by the Town of Canton would not allow in increase in height. Avon did, or currently is looking at the statewide system. I’m not sure but a couple of days ago I heard a trooper or radio tech on the dispatch #1 TG out of the Litchfield Barracks refer to Huckleberry Hill Rd in Avon. Just a guess but I’d say Avon is still investigating the possibilities of using the statewide system. I say this because the road mentioned is where they have always experienced poor reception in the past. But then again, it could merely be a trooper following up on a case and the address just happened to bring him to Avon.

 

[Kitn1mcc]

Also we have some area with great UHF/Low Band tied systems. I am in old lyme we have a combo DMR analog system

 

[Firebuff66]

Not going to solve the world's problems in a RR forum thread, but I think most people wish they could see CLMRN do what some states have done which is if they want to be a primary user and have in building coverage they get the locality to contribute to system build out to make up the different from what the state requirements are and what the locality would need.

They are doing that already, but the state system only became robust enough to add more users about a year ago