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Firefighters distrust of digital radio system grows

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#1
On April 16, 2007, firefighter Kyle Wilson was part of a crew dispatched to fight a residential fire in Woodbridge, Va. He died in the line of duty.

A detailed report on the incident recently released by Prince William County Department of Fire and Rescue concluded that problems associated with the use of the county’s Motorola digital trunked radio system contributed to the tragedy. Issues reported by other firefighters during that incident, which was further complicated by strong winds, ranged from signal distortion and transmission failure to radios displaying “out of range” signals.

Fire safety advocates now are encouraging fire departments across the country to study the incident in hopes that future tragedies could be avoided. Prince William County’s fire department, through further tests, concluded that digital portable radios are “extremely vulnerable to poor environmental conditions and interference of digital noise from ambient sources, which negatively impact the ability of emergency personnel to effectively communicate.”
A handful of fire and police departments, fearing the loss of lives, have opted to continue using analog systems even when the rest of their county’s emergency personnel are using digital trunking systems.

The common complaint, which most affects fire departments, concerns the digital vocoder’s inability to differentiate between a voice transmission and background noise - whether a chain saw, sprayed water or personal alarm. Background noise renders the voice transmission distorted and often unintelligible. Another critical problem is that digital radios lose contact inside buildings. “In most cases, it is a very political and sensitive position to abandon expensive technology and go back to something that is old,” said Daryl Jones, owner and president of Telecommunications Engineering Associates, which manages public safety systems throughout the San Mateo area in California. “But many agencies are finding that complaints from line personnel, both in fire and police, are so significant.”
 
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fwradio

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#4
Interesting article if you click the link above and read the whole thing. We deal with a lot of P25 right now, and EF Johnson, Kenwood, and Icom are all moving to the full-rate vocoder. The big M has decided to stay with half-rate. The effect is that Motorola radios have the background noise issue. Any radios with the newer vocoder will still hear the Motorola radios the same way, but put a radio with the full-rate vocoder in the loud area, and one with a full-rate on the other end and you will notice a big difference.

This is a case where the 800-pound gorilla is making the rest of the industry look bad. They have tried to fix the problem with software changes, but it is a matter of hardware.

I have told a lot of the fire departments that we deal with that the best way to ensure coverage inside structures while using a P25 Trunked system is to have a conventional analog channel on scene linked back to the trunked talkgroup through a vehicular repeater. New building are being built that seem to be "RF Proof." No matter what you do to the radio system outside of the building, there are just some buildings that you will not penetrate from a tower site a few miles away.
 

MrRevesz

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#5
After reading the article, which was very interesting... I couldn't help to think that some of the spokesmen or whatnot for the radio business were blaming the problem of the radios on the Firefighters themselves?
 

citylink_uk

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#6
This is why we insist on using analogue simplex for Fireground and only use the digital system to contact the control room.

You cant be 100% sure that you will be able to get a good signal out of the building, let alone a tower site.
 
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#8
This is in no way a new problem. This has been an issue since day one for the digital systems. There was a book written about the New York Fire Department that that covered the same issue SEVERAL years ago. It seems things STILL have not improved for these radios at fire ground!

I believe the book was "Betrayed".

Also there is a website with SEVERAL articles and reports on these issues as well, including homeland security analysis.

I will try to find the site.

Regards,
 
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#9
On April 16, 2007, firefighter Kyle Wilson was part of a crew dispatched to fight a residential fire in Woodbridge, Va. He died in the line of duty.

Old news??????
 
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#10
Well...

I hate to say this, but, I have to blame the city or county fathers (politicians) for this.

It is clear that they (on this call) went beyond their system's "area of coverage" hence the "NO SIGNAL" issue on their radios.

It isn't the systems fault that happened.

I'd bet if you go back to the ORIGINAL specs for their system, you'll see that it "came in over budget" and the politicians made a conscious decesion to "cut" something (a tower or relay site) out of the system. Doing that lead to this situation. They went into an area they were responsible for but had NO CONTACT with their radio system....

One thing we know in Ohio is about street level coverage for portables...Was their system designed for 'STREET LEVEL COVERAGE" for a PORTABLE radio?

In Ohio, you can use a portable statewide. However, they aren't designed for "street coverage" in every area. (AND, we KNOW that up front!) So, what happens is, you get too deep into a concrete or metal structure, NO SIGNAL from the towar & no communication capability.

Columbus, Cincinatti, Cleveland, Dayton are a few areas that actually have STREET LEVEL COVERAGE that allows you to get deep into a building and still use a portable unit.

I might be wrong, but in almost every case, this is what I've seen happen....

I suppose what is so sad about this type of incident is, it COULD HAVE BEEN AVOIDED if the powers that be LISTENED to their system designer and bought WHAT WAS NEEDED to do the job (at the street lever coverage) for their public safety services....

I'm NOT a radio salesman. I've worked in public safety communications now for over twenty nine years. I've seen a lot of changes come down the pike. I've seen how the politicisns want to "scale back some" on communications purchases.

Your chief's of police and fire/EMS managers must STAND THEIR GROUND on these issues or they will CONTINUE to occur. If they can't convince the powers that be to fork over the TOTAL cost, they better stay where they are at as far as radios....

I'll stop now.... :confused:

Steve/KB8FAR :(
 

KAA951

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#11
AlabamaRS said:
On April 16, 2007, firefighter Kyle Wilson was part of a crew dispatched to fight a residential fire in Woodbridge, Va. He died in the line of duty.

Old news??????
In depth investigations into the causes of a fire fatality don't happen overnight...

Maybe I don't understand your post- I don't think the death of a firefighter is ever "old news"- and it is important to put this information out so we do not repeat the errors that led to his death.

I was at a residential fire just last week where we were at the edge of our coverage area and all the radios gave the big M "bong" and out of range. We had to go individually to each firefighter at the scene to have them switch to one of the Mutual Aid talk-around channels so we would at least have fireground comms.
 
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#13
Certainly there are some upgrades to the system that could be done but here are some observations:

As someone who uses the PWC system, all be it not from a Fire standpoint, it is a vast improvement over the UHF and VHF analog convential systems the county had prior to this system. P25 audio is in my opinion most times much clearer than what the old analog system was at least for police. Fire previously had a simplex VHF system. A couple of observations about the system...

1. System coverage east of route 1 sometimes is lacking due to the low terrain.

2. The system has a tendancy during high stress, high traffic times to either give reject "bonks" or end up with people stepping on each other.


I believe the later is more of an operator error issue than a system issue. On fire scenes such as this and police emergency calls everyone is trying to get on the radio at the same time and no system will respond well to this. The other thing I believe is that police radios and batteries are probably maintained better as each officer is individually issued a portable which is not the case with fire where the radios are used 24 hrs a day. The other part is that police batteries are swapped out and charged/conditioned every shift which probably not the case with fire. Just a few observations...overall our system has excellent coverage most times and the XTS-5000 has worked out well from a police standpoint...granted the only time my radio gets soaked is if im directing traffic in inclement weather and that doesnt compare to water stream from a hose. Also I can count on one hand the amount of dead spots in the county so its really not as bad as some on here seem to think it is.

This truely was a tragedy but Kyle did not die because of faulty technology
__________________
 
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Jay911

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#14
This comes down to the problem of digital systems being sold as a drop-in replacement for analog systems in the same footprint. Is that the fault of the city/system owner? Unable to say without seeing their RFP and confirming whether or not they required the vendor to provide adequate coverage/reliability/QOS. Is it the fault of the vendor and/or its salesmen? That's hard to say, because the vendor is most likely providing what was asked for - albeit pushing the most expensive and advanced system available, whether it's needed or not.

Is it the fault of the firefighter or his direct superiors? Absolutely not!

Fireground communications have no business being on comm systems that are dependent on reaching a distant tower/system. This is true regardless if the voice audio path is analog or digital of any sort. The situation is exacerbated when the audio is rendered digitally, because digital has a much lower tolerance for maintaining a weak/fringe signal - regardless what people tell you. Fireground comms need to be either on simplex or some kind of mobile repeater or mobile trunk site. When you get to that point, it won't matter in most cases if it's analog or digital - the signal will be strong enough to be reliable in either audio format.

In my local area, the fireground channels are primarily trunked talkgroups, mainly because of the desire to be able to interact with responders coming in from a wide area, plus having the ability to have the comms recorded at the dispatch center along with the other dispatch channels. There are simplex channels available if trunk talkgroups can't be reliably used on the fireground, but they are not monitorable by dispatch (thus no emergency button activation is possible), and there is no recording or wide-area usage. There is a rarely-used system of conventional mobile repeaters installed on our rescue trucks, so that if what I'll call "medium" area coverage (far from the "wide" area covered by the entire trunk system, but wider than the area covered by simplex) is required, a conventional repeater channel can be established on the fly. I anticipate this being taken to the next level in future upgrades to the system and/or new comms networks being built, such that I would like to see an entire mobile trunk site deployable at a fireground scene. It would obviously cost more, but it would be able to have the strength required to penetrate the building (so that signals are not lost), plus the properties desired of trunked/dispatch monitored communications. I can envision such a site deployable on the rescues in the same manner as the existing mobile conventional repeaters, but with the addition of a microwave link to a parent site on the trunk system, basically adding a temporary daughter 'site' to the trunk system for the duration of the incident. If a TV crew can put up a mast and get a full video/audio MW/sat link in a matter of minutes, it shouldn't be too hard for a fire department to accomplish the same for simple telephony. The technology is already out there now for the telco's cell industry, with SatCOWs and SatCOLTs - mobile, deployable cell sites on wheels (W) or light trucks (LT).

Anyway, I'm getting off target. The communications problem that arises on a fireground is caused by inadequate penetration of the signal into the fireground/structure, regardless of the communication's properties (analog/digital). The solution is to ensure that the signal has enough strength to reach its users 100% of the time. Period.
 
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#15
It's also well known from brush fire fighters that major fires will, not may, mess up radio communications that must pass through the fire header. Digital or Analog, it doesn't matter. Firefighters on opposite sides of a canyon full of fire can SEE each other, and can't get a signal. Superheated air is not kind to radio propagation.

Add in weak signal area, possibility that the actual fire got between the nearest tower and the firefighters, and 'digital' may have been the least of their real problems.

Not saying that vocoder/background noise trouble might not contribute, just that you shouldn't jump off and make this a 'digital problem' alone.
 
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#17
Issues!

Samuel said:
Certainly there are some upgrades to the system that could be done but here are some observations:

As someone who uses the PWC system, all be it not from a Fire standpoint, it is a vast improvement over the UHF and VHF analog convential systems the county had prior to this system. P25 audio is in my opinion most times much clearer than what the old analog system was at least for police. Fire previously had a simplex VHF system. A couple of observations about the system...

1. System coverage east of route 1 sometimes is lacking due to the low terrain. This is where another tower or realy station could fix the issue. If they know it is occuring, BUY WHAT IS NEEDED to straightwn out the issue!

2. The system has a tendancy during high stress, high traffic times to either give reject "bonks" or end up with people stepping on each other. Again, another "equipment" issue. How many freqs are AVAILABLE for fiels personnel to operate on. It sounds to me like they are a few short. If you have enough freqs built into your system, no one will get "bonked" out!

I believe the later is more of an operator error issue than a system issue. On fire scenes such as this and police emergency calls everyone is trying to get on the radio at the same time and no system will respond well to this. The other thing I believe is that police radios and batteries are probably maintained better as each officer is individually issued a portable which is not the case with fire where the radios are used 24 hrs a day. The other part is that police batteries are swapped out and charged/conditioned every shift which probably not the case with fire. Just a few observations...overall our system has excellent coverage most times and the XTS-5000 has worked out well from a police standpoint...granted the only time my radio gets soaked is if im directing traffic in inclement weather and that doesnt compare to water stream from a hose. Also I can count on one hand the amount of dead spots in the county so its really not as bad as some on here seem to think it is. If you have a "few" areas that are dead spots, why don't thwy try adjusting or change antennas at the tower site(s) to a better gain antenna. Get the signai IN/OUT if your low areas....Steve
This truely was a tragedy but Kyle did not die because of faulty technology
__________________
See above in blue !!!

Steve/KB8FAR :confused:
 

Jay911

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#18
As Steve says, and as others imply, the issue in many cases is infrastructure. There was a trunk system in my area for a number of years that was owned by a town and operated for its public works, fire, and EMS services. I-calls and phone patches were allowed on the system. The crazy thing is, this was a three-frequency system, with one frequency obviously for the control channel. So, routinely, if, say, a car crash came in during normal hours of business, whichever agency was slowest to get to the radio would be essentially without comms for the first part of the incident, because 2 voice channels divided by 3 agencies (and with PW yapping all day about their mundane junk) equals someone ending up missing out. Even worse was when PW was yapping and another PW member was using the phone patch to call home to ask his wife what she was making for lunch. Then, both voice channels are locked up, and neither emergency services agency could get through. Now, whose fault is that - the city, for buying a system with so few channels? The vendor, for selling it to them? Either party, for not configuring the EMS/fire agencies so they'd bump off PW when an emergency call was in progress? Hard to tell. Did anyone plan this system? Who knows?

Too many places put their emergency services on either their corporate/PW trunk or a new trunk/system set to mirror their existing service, without contemplating the fact that emergency services communications needs are much different than when you're driving a grader or picking up garbage cans. It has to work - period - when you're in the 3rd sub-basement of a high-rise, or flying at 150mph over the city in a helicopter. Some vendors are good and will tell a customer when they are overlooking that kind of thing, but some go with the fallacy that 'the customer is always right' and give them just what they ask for, nothing less and nothing more (at least until the contract for future service & maintenance is being negotiated!).

I think we all agree that the answer is that emergency services workers must be "in" on any comm network builds or planning, and when some beancounter decides you can get by with 3 sites that cover 90% of your city 90% of the time, someone jumps up on the table and points out how bad an idea that is.

I still retain that any incident which involves emergency services workers' injury or death, where communications issues were at all questioned in the situation, is the "fault" of either the comms vendor or the people who purchased it. About the only time I'd be willing to lay blame on the responders themselves, when communications played a role in the incident, is if they were supposed to be using channel X and failed to do so, staying on channel Y, or something similar. The firefighter trapped in a basement with no air has no way of affecting the fact that his city didn't put up enough towers to allow his digital, trunked radio transmission to get out of the basement, reach the trunk tower site, and travel back to the incident command bus 50 feet away from him parked in the front yard.
 

Grog

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#19
As I have said many times over the years, fireground ops should be on simplex at all times. It's bad when I hear units operating on a repeater, even worse when they are on a trunked system.

My county does have three simplex fireground channels setup so dispatch can still monitor and call command on them, but the units on scene can actually hear each other, and simplex will cover at least 95% of the fire scenes out there.

Digital use on a fireground is an even worse idea, but that's be rehashed enough..
 
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#20
I have observed the background noise, not human voice or other mechanical noise, just the radio itself which we're using a MA/COM M7100. It's very intersting to note on this because the other radios, the Maxtrac, Spectras, or the EFJ's dont exhibit this noise.
rcvmo
 
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