Public Safety Repeater to boost in building coverage

[BlueDevil]

Any suggestions for a public safety grade repeater product that can be installed in large commercial or industrial buildings to boost or improve radio coverage inside the building?


Sent from my iPhone using Tapatalk

 

[Mr_Boh]

BDA or Bi Directional Amplifier. Look it up. Be prepared for sticker shock. Also look up distributed antenna system.

 

[mmckenna]

There are two ways of doing this…
BDA's are pretty common.
Another option, if you have access to the repeater, is to tap RF off it, covert to optical fiber, then redistribute inside the buildings.

As Boh says, not cheap.

Not sure what your knowledge is on these systems, but a few things to consider:
1. You will need to work with the AHJ (Agency Having Jurisdiction) before you install one of these. Since you will be retransmitting their signal, and that creates a possibility of interference, they need to know.
2. International Fire Code section 510 and NFPA 1221 apply. That makes installation expensive.
3. They are not something you install on your own like a cellular BDA. They need to be engineered and approved for the application. The AHJ also may require annual re-inspections of the system.

There are a bunch of manufacturers out there that make good systems. However, you need to find an engineer who will design the system for you based on the frequencies and coverage needs. That'll dictate the type of system you need.

A good place to start with this sort of stuff is Fire Code Compliance | Public Safety Radio Indoor RF Coverage | RFSignalman.com Paul Niemann is a real easy guy to talk to and he's probably one of the real experts in the field. Looking around on the website would be a good first step. If you have questions, give him a call or e-mail. He can probably point you to a local engineering firm that can help you out.

 

[BlueDevil]

Thanks for your quick replies. We have some buildings in our area that have no radio coverage inside of them. These also happen to be buildings that we (Fire/EMS/LE) respond to often.

I think that if it was approach correctly we may be able to get the building owner to fund these systems.

I will definitely do some reading and further research. Definitely not something that I will be out installing myself on the weekend.

 

[RFI-EMI-GUY]

Keep in mind, that BDA /DAS systems are not something you can buy off the shelf.

You can of course, just buy the stuff, but really you need to measure the actual signal levels in and around the building and mainly treat the dead spots. The system must be engineered by someone with a good deal of RF propagation experience. Also the system needs back up battery and failure monitoring to meet NFPA requirements.

Also, regardless if the signal is delivered via fiber, or using a donor antenna to pick up over air, the signal from the "booster" in the building will be delayed somewhat (worse with DSP and channelized amps). So expect that you might have signal distortion near windows inside and outside the building. If it is a P25 system, extra care is required.

In Miami a while back, a new high rise building was being built, the County told the developer they needed to ensure Public Safety coverage in the building. The designers took this very seriously and put distribution amps and antennas on every floor. The building radiated interference like a 70 story Christmas Tree. Rarely do you need a DAS above the first two or three floors plus basement and garages.

One more thing, the "talk back", signal from the BDA to your repeater receivers has to be carefully adjusted or the noise floor from the BDA becomes a significant factor in the effective sensitivity of your repeater. I have seen this happen, where the installers turned up the system without a tech or engineer being present to set the gain.

Sent from my SM-T350 using Tapatalk

 

[mmckenna]

I think that if it was approach correctly we may be able to get the building owner to fund these systems.

Correct. Many cities/counties are now making this part of the building code. If they require compliance with the latest versions of the NFPA code, they can be required to do it on NEW CONSTRUCTION.

Forcing them to do it on an existing building will be a much harder task.

 

[lmrtek]

For a fraction of the cost you can try some passive repeaters first to see if they may get the results you want.
.
Simply aim a high gain yagi at the tower you are trying to hear then connect it via a short run of low loss coax to another antenna inside the building.
.
You can always add a BDA between the two antennas later if you need more signal.

 

[mmckenna]

You can always add a BDA between the two antennas later if you need more signal.

This is exactly what causes interference. Improperly designed system without proper engineering, design and installation that puts first responders lives at risk.

 

[kayn1n32008]

This is exactly what causes interference. Improperly designed system without proper engineering, design and installation that puts first responders lives at risk.

Bingo. Half assing it is a good way to get people killed.


Sent from my iPhone using Tapatalk

 

[gesucks]

This is exactly what causes interference. Improperly designed system without proper engineering, design and installation that puts first responders lives at risk.

This is the kind of post why we need a giant LIKE button!!

 

[zz0468]

The only rational way to do this is to hire a company that specializes in installing these systems. Don't be surprised if the installed cost gets into six-figure territory.

 

[mmckenna]

Went to some training on these a month or two ago.
"Dollars per square foot" is a normal range for a system that meets all the current codes. Really easy for this to get in the 6 figure range, as ZZ suggested.

I'm not aware of any code requirements that mandate that existing buildings be upgraded with theses systems, although it's very common for them to be required in all new construction, and by required, I mean you don't get your certificate of occupancy until the system passes all the tests. Trying to force a building owner to install a system on their dime in an existing building will probably be met with lots of backlash.

 

[BlueDevil]

I understand peoples comments about trying out different solutions to resolve radio issues. Most of the time I believe this comments are made from the perspective that a lot of Public Safety agencies don't have the funding to put on of these system in every building they have radio issues in.

However in this case I believe the building owner or occupant should or would be responsible for the cost of installing this system. Now this doesn't mean that since someone else is paying for it the most elaborate and expensive system possible should be installed. That isn't a real positive PR move for the agency requiring the installation.

 

[RFI-EMI-GUY]

I understand peoples comments about trying out different solutions to resolve radio issues. Most of the time I believe this comments are made from the perspective that a lot of Public Safety agencies don't have the funding to put on of these system in every building they have radio issues in.

However in this case I believe the building owner or occupant should or would be responsible for the cost of installing this system. Now this doesn't mean that since someone else is paying for it the most elaborate and expensive system possible should be installed. That isn't a real positive PR move for the agency requiring the installation.

Has your agency considered hiring a ----vendor neutral land mobile radio consultant -----to look into this problem? Regardless whether the building owner pays or your department pays, the integrity of your agency's radio signals will be impacted. The solution might be a new simulcast system in some part of town, or specific BDA/DAS solution that works for each building. This is nothing that should be bought off the shelf, or the responsibility entirely placed in the hands of the building owners. You might not be happy with the end product, even if it is a very elaborate and expensive solution by others.

 

[BlueDevil]

Has your agency considered hiring a ----vendor neutral land mobile radio consultant -----to look into this problem? Regardless whether the building owner pays or your department pays, the integrity of your agency's radio signals will be impacted. The solution might be a new simulcast system in some part of town, or specific BDA/DAS solution that works for each building. This is nothing that should be bought off the shelf, or the responsibility entirely placed in the hands of the building owners. You might not be happy with the end product, even if it is a very elaborate and expensive solution by others.

We are apart of a vendor neutral radio technician consortium with a few other counties in which we work closely with on many different levels. There are dozens of Public Safety agencies that are directly or indirectly involved in this consortium. Since we made this transition a few years ago we have been very satisfied with the outcome. The solutions to our radio problems and issues no longer come from a vendor(s) who love to throw money at the problems. Are radio techs are actually employed by a local municipality.

One of our issues is that we just don't have the money to put up a brand new full simulcast site or even just a voter/receiver site.

Here is a very basic Map that I have created to give a visualization of our County Wide simulcast system that I use for some of the Radio/Communications classes I put on.

 

[RFI-EMI-GUY]

We are apart of a vendor neutral radio technician consortium with a few other counties in which we work closely with on many different levels. There are dozens of Public Safety agencies that are directly or indirectly involved in this consortium. Since we made this transition a few years ago we have been very satisfied with the outcome. The solutions to our radio problems and issues no longer come from a vendor(s) who love to throw money at the problems. Are radio techs are actually employed by a local municipality.

One of our issues is that we just don't have the money to put up a brand new full simulcast site or even just a voter/receiver site.

Here is a very basic Map that I have created to give a visualization of our County Wide simulcast system that I use for some of the Radio/Communications classes I put on.

Have you considered a vehicular mounted repeater for penetration into large structures? There are some NFPA requirements that may need to be met such as logging recorder and monitoring at central dispatch. Some agencies have gone this route due to the complexity and cost of BDA/DAS installations.

 

[Mr_Boh]

Have you considered a vehicular mounted repeater for penetration into large structures? There are some NFPA requirements that may need to be met such as logging recorder and monitoring at central dispatch. Some agencies have gone this route due to the complexity and cost of BDA/DAS installations.

Usually the better path to go. Get some mounted on a Chief/Supervisor vehicle and get some training. Although even the Futurecom DVRS systems can get pricey fast, they are worth the investment for portability. That plus a deployable model like the one they sell in a Pelican case would be very useful for a department. Also typically have quite a bit more power than a typical BDA and doesn’t require nearly the amount of engineering.

I would suggest also adding an antenna switch to the vehicles and make the second port easily available so a tripod mounted antenna could be deployed deeper in the structure/incident area quickly and provide extended coverage.

 

[MTS2000des]

The only rational way to do this is to hire a company that specializes in installing these systems. Don't be surprised if the installed cost gets into six-figure territory.

This part. As someone who spends a lot of time dealing with the fun that BDA/DAS can be, the key here is also hiring a competent firm that specializes in design, implementation and performance testing.

Many local radio shops claim they have expertise, as do some contractors, but ask for their qualifications, resume, and customer list.

If no one on their staff is an ETA certified RF interference mitigation technician, then keep shopping. (Ask for their ETA cert number).

As others have said, BDA/DAS is an art and requires proper design, testing and more testing. If it's done wrong, the least of your worries is a poor performing system. Worst outcomes can mean you can be causing harmful interference to other RF spectrum users around, and of course even worst could mean the interference/poor performance could result in an incident.

Do it right or don't do it at all. BDA/DAS are areas where untrained, unqualified shops and individuals need to stay far away from for everyone's safety.

 

[speedway_navigator]

If no one on their staff is an ETA certified RF interference mitigation technician, then keep shopping. (Ask for their ETA cert number).

I just looked at ETA's site to see how someone could verify a cert but don't see it. I run the minimal amount of javascript to make a site work so I may be missing something, do you have the link?